SNiP 2.05.03-84 Bridges and Culverts ENG

NATIONAL CODES & STANDARDS OF RUSSIA

Bridges And Culverts SNiP 2 . 05. 03- 84

1986

USSR STATE COMMITTEE ON CONSTRUCTION

Мoscow 1986

SNIP 2.05.03-84. BRIDGES AND CULVERTS

CONSTRUCTION NORMS

BRIDGES AND CULVERTS

SNiP 2.05.03-84*

Official Translation

USSR STATE COMMITTEE ON CONSTRUCTION

Moscow 1986

CONSTRUCTION NORM SNiP 2.05.03-84* USSR GOSSTROI

BRIDGES AND CULVERTS

Istead of SNiP 11-Дб 7-62*, CH 200-62 & CH 365-67

Introduced by Ministry of Transport Construction and Ministry of Railway Roads

Approved by Regulation of USSR Gosstroi dated November 30, 1984; N 200

Putting in force January 1, 1986


1) BASIC CONCEPTS........................................................................................................................ 1 GENERAL INSTRUCTIONS ......................................................................................................................................1 LOCATION OF BRIDGES AND CULVERTS ...........................................................................................................2 BASIC REQUIREMENTS TO STRUCTURES...........................................................................................................4 OVERALL DIMENSIONS...........................................................................................................................................6 DESIGN OF BRIDGES AND CULVERTS FOR WATER FLOW ACTION...........................................................11 General Instructions ....................................................................................................................................................11 DESIGN OF CARRYING STRUCTURES AND FOUNDATIONS OF BRIDGES AND CULVERTS FOR ACTION OF FORCES ...............................................................................................................................................13 General Instructions ....................................................................................................................................................13 STRAINS, DISPLACEMENTS, LONGITUDINAL SECTION OF STRUCTURES ...............................................14 TRACK STRUCTURE OF RAILWAY BRIDGES ...................................................................................................16 BRIDGE ROAD OF HIGHWAY AND CITY BRIDGES .........................................................................................17 CONNECTION OF BRIDGE TO APPROACHES....................................................................................................19 WATER DIVERSION ................................................................................................................................................20 OPERATIONAL PARTS ...........................................................................................................................................21

2) LOADS AND FORCES .................................................................................................................23 Combinations of Loads ...............................................................................................................................................23 DEAD LOADS AND FORCES..................................................................................................................................25 LIVE LOADS OF MOVING VEHICLES AND PEDESTRIANS.............................................................................27 OTHER LIVE LOADS AND FORCES .....................................................................................................................40

3) CONCRETE AND REINFORCED CONCRETE STRUCTURES.............................................46 BASIC DESIGN REQUIREMENTS..........................................................................................................................46 MATERIALS FOR CONCRETE AND REINFORCED CONCRETE STRUCTURES CONCRETE .....................51 General Characteristic .................................................................................................................................................51 RATED RESISTANCES ............................................................................................................................................54 Characteristic of Deformability Properties..................................................................................................................57 Reinforcement.............................................................................................................................................................57 Steel Articles ...............................................................................................................................................................59 Design Characteristics of Reinforcement....................................................................................................................59 Coefficients of Reinforcement Working Mode...........................................................................................................60 Design Characteristics for Steel Articles.....................................................................................................................62 Characteristic of Reinforcement Deformability Properties and Ratio of Modulus of Elasticity .................................62 ANALYSIS AS PER LIMITING STATES OF THE FIRST GROUP.......................................................................63 Design as per Strength and Stability ...........................................................................................................................63 General Instructions ....................................................................................................................................................63 Strength Design of Sections Normal to Longitudinal Axis of Member ......................................................................65 Design of Flexural Reinforced Concrete Members.....................................................................................................68 Design of Eccentrically Compressed Concrete Members ...........................................................................................69 Design of Eccentrically Compressed Reinforced Concrete Members.........................................................................70 Design of Centrally Tensioned Members....................................................................................................................75 Design of Eccentrically Tensioned Reinforced Concrete Members............................................................................75 Design as per Strength of Sections Inclined to Longitudinal Axis of Member ...........................................................75 Design of Sections Inclined to Member Longitudinal Axis For Action of Shear Force .............................................76 Design of Sections, Inclined to Member Longitudinal Axis, for Action of Bending Moments ..................................78 Butt Joints Design for Shear........................................................................................................................................78 Local Compression (Bearing Stress) Design...............................................................................................................79 Endurance Design .......................................................................................................................................................80 ANALYSIS AS PER LIMITTING STATES OF THE SECOND GROUP ...............................................................83 Crack Resistance Design.............................................................................................................................................83 General ........................................................................................................................................................................83 Crack Formation Design .............................................................................................................................................85 Crack Opening Design ................................................................................................................................................87 Determination of Deflections and Deflection Angles .................................................................................................90 Structural Requirements..............................................................................................................................................91 Minimum Dimensions of Members Section................................................................................................................91 Minimum Diameters of Untensioned Reinforcement .................................................................................................93 Cover of Concrete over Reinforcement.......................................................................................................................93 Minimum Distances Between Reinforcing Members .................................................................................................94 Anchorage of Untensioned Reinforcement .................................................................................................................95 Stressed Bar Anchorage ..............................................................................................................................................96 Longitudinal Reinforcing of Members........................................................................................................................97 Transverse Reinforcing of Members...........................................................................................................................97 Weld Joints of Reinforcement...................................................................................................................................100


Lap Butt Joints of Untensioned Reinforcement (without welding)........................................................................... 101 Butt Joints of Precast Structure Members ................................................................................................................. 101 ADDITIONAL INSTRUCTIONS TO DESIGNING THE PRESTRESSED REINFORCED CONCRETE MEMBERS............................................................................................................................................................... 102 Embedded Items........................................................................................................................................................ 102 Designing of Piers..................................................................................................................................................... 103 Structure Waterproofing ........................................................................................................................................... 105

4) STEELWORK .............................................................................................................................105 GENERAL PROVISIONS ....................................................................................................................................... 105 MATERIALS AND SEMIFINISHED ITEMS......................................................................................................... 106 DESIGN CHARACTERISTICS OF MATERIALS AND JOINTS ......................................................................... 110 Working Mode and Purpose of Structures ................................................................................................................ 118 Designs ..................................................................................................................................................................... 119 General Provisions .................................................................................................................................................... 119 Strength Design......................................................................................................................................................... 120 CENTRALLY TENSIONED AND CENTRALLY COMPRESSED MEMBERS.................................................. 120 FLEXURAL MEMBERS ........................................................................................................................................ 120 Members subject to Effect of Axial Force with Bending.......................................................................................... 123 Design for Strength and Creep of Steel Ropes.......................................................................................................... 127 Stability Design......................................................................................................................................................... 127 Stability Design for Flanges and Webs of Members................................................................................................ 131 Note Reinforced with Stiffeners ............................................................................................................................... 131 Stability Design for Flanges and Webs of Members Reinforced with Stiffeners...................................................... 132 Effective Lengths ...................................................................................................................................................... 134 Limit Slenderness of Bar Members........................................................................................................................... 137 Design for Endurance of Steelwork Members and Their Connections ..................................................................... 138 Special Features of Design of Load-Bearing Members and Connections................................................................. 140 MEMBERS OF MAIN TRUSSES ........................................................................................................................... 140 MEMBERS OF BRIDGE ROADWAY ................................................................................................................... 142 MEMEBERS OF BRACING.................................................................................................................................... 144 DESIGN OF CONNECTIONS................................................................................................................................. 145 Design Calculation of Connecting Strips and Perforated Sheets .............................................................................. 152 Design Calculation of Bearing Parts ......................................................................................................................... 153 DESIGNING............................................................................................................................................................. 154 GENERAL PROVISIONS ....................................................................................................................................... 154 Section of Members .................................................................................................................................................. 155 Web Stiffeners of Flexural Solid Webs .................................................................................................................... 157 Prestressed Decks...................................................................................................................................................... 159 Welded, Frictional and Bolted Connections ............................................................................................................. 159 Details of Structures.................................................................................................................................................. 162 Design of Connecting Plates and Perforated Sheets ................................................................................................. 164 Particular Features of Bolt-Welded Span Structures................................................................................................. 164 Design of Orthotropic Deck for Roadway Part ......................................................................................................... 165 Structure of Bearing Parts ......................................................................................................................................... 166

5) COMPOSITE STRUCTURES....................................................................................................166 GENERAL PROVISIONS ....................................................................................................................................... 166 DESIGNS.................................................................................................................................................................. 167 General Provisions .................................................................................................................................................... 167 DESIGN OF STRUCTURES ................................................................................................................................... 172 Strength Design......................................................................................................................................................... 172 ENDURANCE DESIGN .......................................................................................................................................... 177 CRACK RESISTANCE DESIGN ............................................................................................................................ 178 DESIGN OF INTEGRATION OF REINFORCED CONCRETE SLAB WITH STEEL STRUCTURE ................ 179 CHECK OF RIGIDITY, DETERMINATION OF CAMBER AND DESIGN OF HORIZONTAL LOADS.......... 180 DESIGNING............................................................................................................................................................. 181

6) WOOD STRUCTURES...............................................................................................................182 7) BASES AND FOUNDATIONS ...................................................................................................182

GENERAL PROVISIONS ....................................................................................................................................... 182 DESIGNS.................................................................................................................................................................. 182 Designing.................................................................................................................................................................. 185 APPENDIX 1*,.....................................................................................................................186

CLEARANCES TO BRIDGE STRUCTURES ON GENERAL HIGHWAYS , INTRA-ECONOMY MOTOR ROADS IN KOLKHOSES, SOVKHOSES AND OTHER AGRICULTURAL ENTERPRISES AND


ORGANIZATIONS, ON ROADS TO INDUSTRIAL ENTERPRISES, AS WELL AS ON STREETS AND ROADS IN CITIES, VILLAGES, AND RURAL SETTLEMENTS.................................................................186

APPENDIX 2........................................................................................................................ 190 COMBINATION COEFFICIENT η FOR LIVE LOADS AND FORCES ........................................................190

APPENDIX 3........................................................................................................................ 192 METHODS OF DETERMINING THE RESULTANT OF CHARACTERISTIC HORIZONTAL (LATERAL) PRESSURE TO BRIDGE PIERS FROM DEAD WEIGHT OF EARTH .........................................................192

APPENDIX 4*...................................................................................................................... 194 METHODS OF DETERMINING COEFFICIENT OF VERTICAL EARTH PRESSURE WHEN DESIGNED LINKS (SECTIONS) OF PIPES .........................................................................................................................194

APPENDIX 5....................................................................................................................... 195 CHARACTERISTIC LIVE VERTICAL LOAD CK FROM MOVING RAILWAY TRAIN AND RULES OF LOADING THE LINE OF INFLUENCE WITH THIS LOAD..........................................................................195

APPENDIX 6....................................................................................................................... 198 EQUIVALENT LOADS FROM SINGLE HEAVY LOADS HK-80 AND НГ-60............................................198

APPENDIX 7....................................................................................................................... 199 EQUIVALENT LOADS FROM SINGLE CARS, STANDING AND MOVING TRAINS OF CARS OF LOAD АБ ........................................................................................................................................................................199

APPENDIX 8....................................................................................................................... 200 METHODS OF DETERMINING HORIZONTAL (LATERAL) EARTH PRESSURE AGAINST LAND PIERS (ABUTMENTS) FROM RAILWAY AND HIGHWAY MOVING VEHICLES..................................200

APPENDIX 9*..................................................................................................................... 202 AERODYNAMIC COEFFICIENT.....................................................................................................................203

APPENDIX 10*.................................................................................................................... 204 CHARACTERISTIC ICE FORCES....................................................................................................................204

APPENDIX 11*.................................................................................................................... 206 LOSSES OF PRESTRESS IN REINFORCEMENT...........................................................................................206

APPENDIX 12..................................................................................................................... 211 DESIGN OF RIGID LINKS OF ROUND REINFORCED CONCRETE PIPES ...............................................211

APPENDIX 13*.................................................................................................................... 211 DETERMINATION OF SECTION RIGIDITY OF REINFORCED CONCRETE MEMBERS FOR COMPUTING DEFLECTIONS AND TURN ANGLES TAKING INTO ACCOUNT CREEP OF CONCRETE.............................................................................................................................................................................211

APPENDIX 14*................................................................................................................... 214 COEFFICIENTS OF CABLE WORKING MODE ............................................................................................214

APPENDIX 15 , .................................................................................................................... 215 COEFFICIENTS FOE STABILITY DESIGN OF BARS AND BEAMS .........................................................215

APPENDIX 16*.................................................................................................................... 218 STABILITY DESIGN OF FLANGES AND WEBS OF MEMBERS SUPPORTED BY STIFFENERS..........218

APPENDIX 17*.................................................................................................................... 226 COEFFICIENTS FOR ENDURANCE DESIGN................................................................................................226

APPENDIX 18*.................................................................................................................... 231 DESIGN OF ROADWAY ORTHOTROPIC SLAB FOR STRENGTH AND STABILITY .............................231

APPENDIX 19...................................................................................................................... 237 ALLOWANCE FOR CREEP, VIBROCREEP OF CONCRETE AND COMPRESSION OF TRANSVERSE JOINTS IN COMPOSITE STRUCTURES.........................................................................................................237

APPENDIX 20...................................................................................................................... 239 DETERMINATION OF STRESSES IN COMPOSITE BEAMS DUE TO CONCRETE SHRINKAGE AND TEMPERATURE ACTIONS..............................................................................................................................239

APPENDIX 21...................................................................................................................... 240 DISTRIBUTION OF SHEARING FORCE ABOVE INTEGRATION JOINT OF REINFORCED CONCRETE SLAB AND STEEL STRUCTURE IN COMPLICATED CASES OF ACTIONS ............................................240

APPENDIX 22...................................................................................................................... 241 STRENGTH DESIGN OF INTEGRATION OF REINFORCED CONCRETE AND STEEL BY FLEXIBLE STOPS AND ANCHORS ...................................................................................................................................241

APPENDIX 23...................................................................................................................... 242 STRENGTH DESIGNS OF INTEGRATION OF REINFORCED CONCRETE AND STEEL BY HIGH-TENSION BOLTS REDUCING REINFORCED CONCRETE .........................................................................242

APPENDIX 24...................................................................................................................... 243 DESIGN RESISTANCE OF BASE SOIL TO AXIAL COMPRESSION..........................................................243

APPENDIX 25*.................................................................................................................... 245


METHOD OF CHECKING THE CARRYING CAPACITY OF SOIL OF PILED OR CAISSON FOUNDATION AS CONVENTIONAL SHALLOW FOUNDATION............................................................. 245

APPENDIX 26.......................................................................................................................246 METHODS OF CHECKING THE CARRYING CAPACITY OF SOIL UNDERLYING STRATUM............ 247

APPENDIX 27......................................................................................................................248 DETERMINATION OF ADDITIONAL PRESSURE FROM WEIGHT OF APPROACHED EMBANKMENT ADJOINING PART ONTO BASE OF ABUTMENT........................................................................................ 248

APPENDIX 28......................................................................................................................249 ECCENTRICAL COMPRESSION STRENGTH DESIGN OF CIRCULAR SECTION OF REINFORCED CONCRETE MEMBERS ................................................................................................................................... 249

APPENDIX 29*....................................................................................................................250 MAIN LETTER DESIGNATIONS OF VALUES.......................................................................................... 250

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The present norms have been used in designing the new permanent bridges and rehabilitation of existing ones (including underpasses, viaducts, overpasses and pedestrian bridges) and in designing the culverts in embankments on the railroads (with 1520 mm track), on underground railroads and tram lines, on motor roads (including intra-economy roads in kolkhozes, sovkhozes and other agricultural enterprises and organisations, roads to industrial enterprises), on the streets and roads of cities, villages and rural settlements. The norms have been used also in designing the combined bridges with traffic on them of highway and city road vehicles and trains of railroad or underground railroad, in designing the carrying structures of bascule bridge spans and pedestrian tunnels under railroads, highways and city roads. Bridges with spans above 33 m long on the industrial enterprises roads with traffic of very heavy trucks can be designed under these norms taking into consideration the requirements for loads and overall dimensions provided by technical assignments. These norms should be observed in designing the bridges and culverts that are intended for performance in any climatic conditions of the country and in regions of designed seismisity up to 9 seismic units inclusively. The present norms are not applied to design: - bridges on railway high-speed passenger lines (200 km/h and more); - mechanisms of bascule bridge spans; - bridges and culverts on in-site motor roads of lumbering and forestry enterprises (not connected to the highways and to water ways); - service trestles and galleries included into a complex of buildings and industrial structures.

1) BASIC CONCEPTS GENERAL INSTRUCTIONS

1.1. *When designed new bridges and culverts and repaired the existing ones the following things should be observed: - requirements to provide reliable, durable and trouble-free performance of structures as well as safe and uniform road traffic, pedestrian safety and protection of labour force in periods of construction and operation; - trouble-free passage of possible floods and ice drift on water courses and besides that the requirements of navigation and timber floating on water ways; - design concepts ensuring economical consumption of materials, fuels and power resources, a decrease of cost and labour of construction and operation.; - simplicity, convenience and high pace of structure erection, wide application of mechanised and automatic devices, application of standard decisions and use of precast structures, members and materials corresponding to standards and technical requirements; - allowance of perspectives for development of traffic transport and highway network, reconstruction of the existing underground and above-ground utility lines and construction of the new ones, improvement and planning of populated areas, future development of lands for agriculture purposes; - measures on environment protection (including against water logging, thermokarst, erosion, icing, and other detrimental processes), on maintaining the ecological equilibrium and on conservation of fish reserves.

1.2. Basic technical concepts applied to when designed the new bridges and culverts and repaired the existing ones shall be confirmed by comparison of technical-economic indices of competitive variants.

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1.3. * The design work on repairing the bridges and culverts should take into consideration physical condition of bridges and culverts, load capacity of structures, duration and schedule of post-rehabilitation operation. When constructed the second lines the design work of railway bridges and culverts should take into consideration the structural features and experience service of structures on the existing line.

1.4. The bridges and culverts shall be designed as capital structures. It is prohibited to design: - wood culverts; - wooden bridges on ways and roads intended for carrying the hot materials (liquid iron steel, slag, etc.). Wooden bridges can be constructed :

a) on railway lines of common network of category below II (SNiP II-39-76) with approval of the Ministry of Communications, on railway lines of industrial enterprises with approval of the customer;

b) on highways of category below III (SNiP 2.05.02-85) with no limitation; c) on arterial streets of regional purpose (SNiP 2.07.01-89*) with approval of:

the city executive committee for the biggest, big , large-sized and middle-sized cities; the regional executive committee for small towns, settlements and rural populated areas;

d) on streets and roads of local purpose (SNiP 2.07.01-89* and SNiP 2.05.11-83) with no limitation.

When concrete or reinforced concrete piers are used for wooden bridges the piers design should take into consideration the replacement of wooden span structures by reinforced concrete span structures.

LOCATION OF BRIDGES AND CULVERTS 1.5. Choice of a place for bridge crossing, breakdown of the bridge into spans, designation of structure position in plan and section shall be performed taking into consideration the requirements of the road alignment (line) or accepted town planning concepts, constructional and operation indices of variants as well as fluvial, geological, hydrogeological, ecological, landscaping and other local conditions influencing on the technical-and-economic indices of the given part of the road (line). In choosing the place for bridge crossing through the navigable rivers it is desired, if possible: to locate bridge in perpendicular to water stream ( angularity not more than 10°) on straight parts with a stable bed, in places of narrow (poorly flooded) flood plain and far from crossovers at a distance not less than 1.5 of length of standard ship or raft make-up; to align the navigable span middle with an axis of the corresponding ship course taking into consideration possible fluvial changes and displacement during estimated service period; to ensure relative parallelism of an axis of ship course, water stream direction and planes of piers facing to the side of navigable spans; to accept an admissible deviation from parallelism of ship course and river stream direction not more than 10°; don’t permit an increase of water stream speed in the bed with design navigable level, that is a consequence of bridge crossing construction, more than 20% with water speed 2 m/s in natural conditions and 10% with water speed more than 2.4 m/s (with water speed above 2m/s to 2.4 m/s in natural conditions the percent of admitted average speed increase should be determined by interpolation); to design, as a rule, a streamlined cross section of the bridge pier within the flooding up to elevation of design navigable level.

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1.6. Dimensions and number of culvert structures on crossing of water course shall be determined on the base of hydraulic calculations, in this case it is necessary to consider the consequent influence of the structure upon the environment. Passage of several water courses through one culvert structure should be confirmed, but in availability of permafrost soil, mud flow, loess soil or possibility of ice forming it is never allowed.

1.7. *. Railway bridges with ballast-mounted rail track, small and medium highway and city bridges1, as well as the culverts are allowed to be constructed on parts of the road (street) of any profile and plan approved for the road (street) under construction. Railway bridges with non-ballast roadway should be located on straight parts of the road, on horizontal grounds or slopes not steeper than 4‰. The mentioned bridges can be constructed on slopes more than 4‰ , and on the railroads of enterprises – on the curves in plan as well, only in availability of feasibility study. Wooden railway bridges with non-ballast roadway can be constructed on slopes up to 15‰ and on curves in plan with radius 250 m and more. The large bridge roadway longitudinal gradient should be not more than, in ‰, 30 for highway bridges; 40 for city bridges; 20 for all types of bridges with a wooden floor.

1.8. * Depth of fill over links or floor slabs of pipes (including pedestrian tunnels), as well as over bridge arches shall be taken not less than one indicated in Table 1*. ________________________________________________________________________ 1 Here and further bridges are classified as follows: small bridges are up to length 25 m, middle bridges are of a length above 25 to 100 m, large bridges are of a length above 100 m. Highway bridges (including city bridges) with a length less than 100 m but with spans more than 60 m are referred to the large bridges. The bridge length should be measured between shore piers ends (embedded boards), in this case transition slab length should not be included into the length of a bridge.

Table 1* Depth of fill, in m, above

Road type reinforced concrete pipes

steel corrugated pipes

vaults of bridges

Railway: of common network and approach railways to enterprises

1.0 1.2 0.7

railways within enterprise 0.4 1.0 0.7 Highways of common use, roads and streets in cities, villages and rural populated areas as well as motor roads to industrial enterprises

0.5

0.5**

0.2

Intra-economy motor roads in kolkhoses, sovkhoses, and other agricultural enterprises and organizations, local-purpose roads ____________

0.2*** - -

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*Measurement from top of the pipe link (floor slab) or from upper point of arch to bottom of the rail - on railway roads, or to bottom of cast-in-place pavement courses - on motor roads. ** But not less than 0.8 m from top of the pipe link to surface of the pavement. *** But not less than 0.5 m to sub-grade edge level. Notes. Depth of fill over reinforced concrete pipes and pedestrian tunnels located within railway station can be accepted less than 1.0 m. In justified cases on streets and highways the depth of fill over pipes and closed chutes can be accepted not less than 0.5 m. In all cases when depth of fill is smaller, it shall be carried out the instructions of allowance for corresponding dynamic effect of live loads, refer to the item 2.22*.

BASIC REQUIREMENTS TO STRUCTURES 1.9. *. Basic sizes of span structures and piers of new bridges as well as of culverts shall be specified with observance of principles of modularity and unification in construction.. Standard designs of railway bridges and culverts should provide the opportunity to use these designs in construction of secondary lines and replacement of span structures on network in service. Designed spans or total length of span structures of highway and city bridges on straight parts of roads with piers vertical and perpendicular to a bridge axis shall be specified equal to 3, 6, 9, 12, 15, 18, 21, 24, 33 and 42 m and multiple to 21 m in case of more long spans. Mentioned sizes should be taken as a total length of sectional span structures: up to 42 m inclusive made of reinforced concrete and up to 33 m inclusive made of other materials. In all other cases as well as of span structures with through main trusses the design spans should correspond to mentioned sizes. Deviation from these sizes is permitted with feasibility study when designing: the bridges to be located near the existing ones; multiple-span underpasses through railway station tracks; wooden bridges with spans less than 9 m , as well as separate spans of complicated bridges (sectional , framed suspended and framed cantilevered ). When the structure includes standard members or standard parts the admissible deviations in geometrical dimensions established for them shall be taken into consideration. For precast members produced for the given structure of the bridge or culvert the design can establish own values of these deviations calculated in proper way.

1.10. Mass and sizes of precast structure members should be specified, as a rule, in terms of possibility to use all-construction and special cranes and trucks of series production when erected and transported.

1.11. Construction of deformation devices (bearing parts, hinges, expansion joints, equalizing devices, season equalising rails) and their position should ensure necessary freedom for inter-moving (linear, angle) of separate parts (members) of the structure. Design documents should include instructions how to install deformation devices taking into account the readiness of construction and the temperature during the closure of the structure in conformity with the requirements of item 2.27*.

1.12. Wing and bank protection works shall be constructed for bridge crossings if necessary to control the flow direction and to prevent erosions (washouts). Embankment wings shall be provided in case of flood-plain discharge less than 15% of rated one or when the average flow velocity under the bridge to the washout is more than 1 m/s, as well as in case of relevant situation features of crossing (pressed currents, river arm closure, etc.)

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Culverts and small bridges should provide, on the base of hydraulic calculations, the dredging, levelling and consolidation of beds, the devices preventing the accumulation of loads as well as the devices for damping the flow water velocity at inlet and outlet. When construction uses the concept of conservation of permafrost the erection of wing and bank protection works should not caused damage of conditions of ground water running, local water stagnation and other significant changes of domestic regime of water course, as well as change of condition of permafrost soils in the base.

1.13. Opening (and clear height) of culverts should be specified, as a rule, in m, not more than: 1.0 – for pipe (or distance between manholes in centre of tracks) up to 20 m long; 1.25 - for pipe 20 m long and more. Opening of culverts on motor roads lower than category II can be specified , in m: 1.0 - for pipe up to 30 m long; 0.75 - for pipe up to 15 m long; 0.5 - on slip roads with high-velocity channel arranged within the pipe (slope 10‰ and more),

and with a guard at the inlet. In reasonable cases, on streets and roads of local purpose as well as on irrigated lands, in villages and rural populated areas on highways of category lower than category II, with the approval of Motor Roads Ministries of the Republics it is allowed to apply culverts of opening 0.5 m with a pipe up to 15 m long with high-velocity channel arranged within the pipe (slope 10‰ and more) and with a guard at the inlet. It is permitted to accept 0.5 m opening for culverts on the intra-economy motor roads (as per SNiP 2.05.11-83) with a pipe 10 m long and less. Openings of culverts on common railroads and common highways in regions with mean ambient air temperature of the most cold five days below –40° C (with probability 0.92 as per SniP 2.01.01-82) shall be specified not less than 1.5 m not depending on a pipe length. Openings of culverts and small bridges can be enlarged for using them for pedestrian and cattle crossing and in availability of technical-and-economic feasibility study for motor road vehicles (low, narrow-grip agricultural machines), providing the relevant overall dimensions.

1.14. Culvert pipes should be designed, as a rule, for pressureless mode of operation. Culverts located on common railroads can work in half-pressure and pressure modes to pass only small discharge, and on all other roads to pass only computed discharge (see the item 1.25*). At this, the pipe heads and links should be fitted with foundations, and if necessary, with curtains. Besides that, pressure mode of operation should provide special inlet heads and should ensure watertightness of joints between the face ends of the links and foundation sections, as well as reliable consolidation of the bed, stability of the embankment against head and filtration. For culverts located in regions with mean ambient air temperature of the most cold five days below -40° C it is prohibited to provide half-pressure and pressure mode of operation, except the cases when culverts are laid on rocky ground.

1.15. Culverts, as a rule, shall be designed with inlet and outlet heads which shapes and sizes ensure calculated conditions of water flow and stability of an embankment surrounding the culvert. Steel corrugated pipes can be designed without heads. In this case the lower part of uncut pipe should protrude from the embankment at a level of its foot not less than 0.2 m, but the section of pipe with cut end should protrude from the embankment body not less than 0.5 m.

1.16. *It is prohibited to use culverts in availability of drift ice and drift wood as well as in places of possible mudflows and icing field.

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In places where icing field can occur it is allowed, as an exception, to use rectangular reinforced concrete culverts (not less than 3 m wide and 2 m high) in complete with permanent anti-icing works. At this, lateral walls of a culvert shall be made of thick concrete. To let the mudflow pass it is necessary to provide one-span bridges with opening not less than 4 m or to provide the mudflow descents with minimum restriction of the flow.

1.17. Design plans and specifications should provide necessary measures on protection of members and parts of bridges and culverts from damage while constructing the embankment and consolidating the slopes, against blocking and dusting, harmful action of aggressive medium, high temperature, stray currents, etc.

1.18. For newly designed bridges a distance between neighbouring main trusses (beams) should be accepted taking into account the conditions of inspection, routine maintenance and painting of separate parts of the structure. In case of separate superstructures (for each track or roadway in one direction of vehicle traffic) a clear distance between the adjacent main trusses (beams) should be specified not less than 1.0 m.

1.19. Structural concepts in designing the small railway bridges with driving on the ballast should provide a possibility to lift the track up when capital-repaired.

OVERALL DIMENSIONS 1.20. *Obstruction clearance of designed structures should satisfy the requirements of: GOST 9238-83 on the railway roads; GOST 23961-80 on lines of underground railway; Obligatory Appendix 1* on common highways, intra motor roads of kolkhoses and sovkhoses and other agricultural enterprises and organizations1, on roads of industrial enterprises as well as at streets and roads in cities, villages and rural populated areas. If a perspective plan of road network development or technical grounds for the designing provide a transfer of a road to more high category, in this case the obstruction clearance of the designed structures as well as their load capacity should correspond to the requirements provided for structures on the roads of more high category.

1.21. *The width of pedestrian bridges and tunnels shall be determined in respect to perspective calculated volume of pedestrians per “hot” hour and be specified not less than 2.25 m for bridges and 3.0 m for tunnels. The pedestrian tunnel clear height should be not less than 2.30 m. The mean calculated carrying capacity of 1m width shall be specified as 2000 man/h for pedestrian bridges and tunnels and 1500 man/h for stairs. The width of pedestrian bridges and tunnels constructed outside the populated areas can be specified as 1.5 m. The structure clearances for field roads and animal crossing (wild animal migration) in absence of special requirements shall be specified as follows :

a) for field roads: not less than 4.5 m high, and 6.0 m wide, but not less than a value increased by 1.0 m of maximum width of agricultural machines allowed to run.

b) for animal crossing: not less than 3.0 m high, a width is according to formula 2+λ/6, where λ is a length of animal crossing, but not less than 4.0 m and not more than 8.0 m.

________________________ 1 Further, in cases when it is easy to understand the meaning of expression “intra motor roads of kolkhoses and sovkhoses and other agricultural enterprises and organizations”, it will be substitute for the short expression “ intra-economy roads”.

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The field road or road for animal crossing running under the span of the bridge or in the culvert under the fill shall be consolidated all over the entire width and shall be strengthened on parts not less than 10.0 m each direction from the structure. The structure is fitted with directional safety guard, if necessary.

1.22. *The clearances of navigation spans on the inner water ways should be accepted in conformity with GOST 26775-85. When constructing the bridges for the second track or additional lanes for motor traffic (the case of widening the existing bridge crossings) the under-bridge clearances should be specified on the grounds of technical and economic calculations taking into consideration the under-bridge clearances of the existing bridges.

1.23. *Position of bridge members above the level of water and drift ice on non-navigated and non-floating water courses as well as in non-navigated spans of bridges on navigated water ways should be defined depending on the local conditions and selected bridge diagram. Superelevation of separate members of the bridge above the appropriate level of water and drift ice in all cases should be not less than values given in Table 2. Superelevation of superstructure bottom above the maximum static level of water pool near the bridges positioned in non-navigated and non-floated zones should be not less than 0.75 of a height of designed wind wave with magnification by 0.25 m.. The minimum superelevation of superstructures bottom in availability of ice field shall be specified taking into consideration their heights. In availability of ice field simultaneously with wood drift the superelevation values given in Table 2 shall be magnified not less than by 0.50 m. The clear distance between piers in availability of wood drift shall be specified taking into consideration size of woods, but not less than 15.0 m.

1.24. The clear superelevation of the highest point of inner surface of the culvert pipe in any cross section above the surface of water in the pipe at maximum flow of designed flood and non-pressure mode of operation shall be: in round and vaulted culverts up to 3.0 m high - not less than 1/4 of the pipe height; above 3.0 m - not less than 0.75 m; in box culverts up to 3.0 m high - not less than 1/6 of the pipe height, above 3.0 m - not less than 0.50 m.

SNiP 2.05.03-84 Page 9

Table 2 Superelevation of parts or members, m Superelevation of parts or members, m Part or member of bridge

above water level (taking into account an action of backwater and a wave) at maximum flood discharges

above the highest level of drift ice

Part or member of bridge

above water level (taking into account an action of backwater and a wave) at maximum flood discharges

above the highest level of drift ice

calculated for bridges calculated for bridges on

railway roads of common purpose

on other railway roads and on all motor roads

maximum

on railway roads of common purpose

on other railway roads and on all motor roads

maximum

Bottom of superstructures: a) at a depth of back-

water 1 m and less

0.50 0.50 0.25 - Top of the ground for installation of bearing parts Bottom of springing of arches and vaults

0.25 0.25

0.25 -

-

0.50 0.25

b) ditto, above 1 m 0.75 0.50 0.25 0.75 c) in availability of ice

dams on the river d) in availability of

drift wood e) in availability of

mudflows

1.00 1.50 -

0.75 1.00 1.00

0.75 1.00 1.00

1.00 - -

Bottom of longitudinal braces and protruding members in spans of wooden bridges

0.25 0.25 - 0.75

Notes. 1. For small bridges it is allowed to determine the smallest supervision of the superstructure bottom not taking into account a height of a wind wave 2. In availability of phenomena causing the higher levels of water ( as a result of backwater from down rivers, lakes or storages, wind-induced surge, formation of dams or passing of floods by channels, covered with ice, etc.) the superelevations given in Table should be calculated from this level,

which probability of superelevation is set in accordance with Table 3*. 3. In determining the superelevation of the top of the ground for mounting the bearing parts the water level should be defined taking into consideration the flow surge to the bridge pier.

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Table 3 Railway roads Highways, city streets and roads

Structures Category of road Probability of exceeding the maximum discharges of floods, %

Structures Category of road Probability of exceeding the maximum discharges of calculated floods, %

calculated maximum Bridges and culverts I and II (general

network) 1 0.33 Middle-size and small

bridges I-III, 1-в, 1-к and II-к and city streets and roads

1***

Ditto II and IV (general network)

2 1* Ditto IV, II-в, III-в, III-к, IV-в and, IV-к, V, I-с and II-с

2***

Ditto IV and V (access road)

2** - Small bridges and culverts

1 1****

Ditto Inner tracks of industrial enterprises

2 - Ditto II,III,III-п and city streets and roads

2****

Ditto IV, IV-п, V and intra-economy roads

3****

• In calculating the verges of subgrade, non-flooded regulation structures and protection dams of divagative river channels for railway roads of category III, the probability of exceeding the maximum discharge of maximum flood should be accepted as 0.33%

** If an enterprise can not interrupt the traffic by the technological reasons, the probability of exceeding should be accepted as 1%. *** In regions with poor developed motor roads network the probability of exceeding is permitted to accept 0..33 instead of 1% and 1 instead of 2% for structures of very important economy significance, in availability of feasibility study. **** In regions with well developed motor road network for motor road small bridges and culverts, in availability of feasibility study, the probability of exceeding is permitted to accept as 2 instead of 1% and 3 instead of 2%, and 5 instead of 3% and for culverts on roads of category II-c and III-c , it is 10%. Note. The extent of development of motor roads network in region of construction and importance of designed structures for national economy are established in technical grounds for development.

SNiP 2.05.03-84 Page 11

DESIGN OF BRIDGES AND CULVERTS FOR WATER FLOW ACTION GENERAL INSTRUCTIONS

1.25. *Bridges, culverts and flood-plain fills shall be calculated for water flow action, as a rule, by hydrographs and gage curves of designed floods. Besides that, the bridges, culverts and flood-plain fills on common railway roads shall be calculated by hydrographs and gage curves of designed floods conventionally called as the largest ones. At this, probabilities of exceeding the designed floods and the largest ones shall be accepted the same with given in Table 3* probabilities of exceeding the maximum flows of corresponding floods. When hydrographs and gage curves of floods are not available as well as in other reasonable cases, the structure can be calculated for water flow action by maximum flows and relevant stages of designed and maximum floods. Calculations should take into consideration the experience of closely located culverts on the same water course, the influence of culverts to each other and also the influence of existing or planned hydraulic structures and other river facilities upon the designed culverts. If engineering works, buildings and agricultural lands are near the bridges and culverts it is necessary to check their safety against underflooding due to the backwater in front of the structure. Designing of culverts close to non-capital dams should take into account the possible flushes in these dams. The decision whether to strengthen the dam or to enlarge the culvert opening shall be made in system, by means of comparison of technical and economical indices of available designs.

1.26. Calculations shall take the maximum flows of floods of the origin that create the most unfavourable operation conditions at a specified value of probability for exceeding. Construction of hydrographs and gage curves, determination of maximum flows during different floods and corresponding to them water stages shall be carried out in conformity with the requirements of SNiP 2.01.14-83.

1.27. Sizes of small bridge and culvert openings can be determined by the water flow mean velocity permissible for river-bed soil (including at inlet and outlet of the structure), types of bed consolidation and cones consolidation, in this connection the requirements given in items 1.23*, 1.24 and 1.34* shall be observed. Openings of small bridges and culverts can be specified taking into account water accumulation near the structure. Decrease of water flow in structures due to water accumulation is possible not more than 3 times if size of opening is specified by storm runoff and 2 times if size of opening is specified by snowmelt runoff and there is no ice or other phenomena decreasing the size of the opening. At this, not depending upon the kind of designed runoff, the culverts should keep the instructions of item 1.14 or 1.24 depending on a character of their operation in conditions of accumulation, and the small bridges should keep the item 1.23* requirements for the bottom position of the structures. If there is a permafrost soil, water accumulation near the structure is not allowed.

1.28. Sizes of openings for large and middle bridges shall be determined taking into account the backwater, natural deformation of river-bed, stable widening of under-bridge bed (cutting), general and local scours at the piers, cones and regulating structures. The bridge clear opening shall be not less than a stable width of the river-bed. City bridge opening sizes shall be specified taking into account the planned regulation of a river and the requirements for embankment layout.

1.29. General scour under the bridges shall be calculated by the equation of sediment balance on sections of the river-beds near the bridge crossings during the floods as specified in item 1.25*. If a pass of floods, smaller in quantity than the designed (maximum) ones, causes irreversible change in under-bridge bed (this is possible with flow closed more than 2 times, on bridge crossings in conditions of backwater, in tail bays of dams, deformation of beds in plain openings, etc.), then general scour shall be determined from conditions of passing the designed (maximum) flood after a series of full-scale observed floods of one of the high-water periods.

SNiP 2.05.03-84 Page 12

For preliminary calculations and in lack of required data on water course regime, general scour can be determined by flow velocity corresponding to the sediments balance. When morphometric basis of calculation is used, the calculated maximum depth of general scour requires a 15% increase.

1.30. While constructing a line of maximum scours, besides general scour it is necessary to consider local scours at piers, influence of regulating structures and other elements of bridge crossing, possible natural changes in the bed and features of its geological structure Calculations of bridges for action of seismic loads shall not include local scour of river bed at piers.

1.31. *Coefficient value of general scour under the bridge shall be confirmed by technical-and-economical analysis. At this, it is necessary to consider the kind of river-bed soils, the bridge pier foundation structure and its embedding depth, division of bridge to spans, the backwater values, possible bed widening, flow velocity allowable for navigation and fish migration, and also other local conditions. The scour coefficient value shall be taken not more than 2, as a rule. Notes. In reasoned cases general scour coefficient can be taken more than above mentioned for bridges through shallow rivers and water courses

1.32. *Cutting of soil in the flood-plain part of the bridge opening can be carried out only in the lowland rivers. Size and shape of the cut shall be determined by calculation on the condition that the cut is not drifted in dependency on frequency of flood-plain flooding and degree of the flow closing with a bridge crossing at a designed level of high water. When calculating the free area under the bridge, the cut of shoals and banks in the channel is not considered.

1.33. The widened part due to cutting the soil under the bridge shall smoothly be tapered to unwidened parts of the channel in order to create favourable conditions for water flow and channel-forming drifts to under-bridge section. Total length of cut (to upstream and downstream from the central line of crossing) should be 4-6 times more than its width in section line of a bridge. Section line of heads of regulating structures should avoid the cut shape of maximum width. When designed the soil cutting in the flood plain, it is necessary to remove silt deposit up to the exposed loose alluvial soil on the whole cut area.

1.34. *Superelevation of edges of soil constructions on the approaches to large and middle-sized bridges above water level during floods as per item 1.25 (taking into account climb of wave on slopes and possible backwater) shall be specified not less than 0.5 m for the subgrade, water-separating and protecting dikes, and also for training walls in rivers with divagation channels, and 0.25 m for regulating structures and berms of embankments. Superelevation of subgrade edge on the approaches to small bridges and culverts above water level during the floods as per item 1.25 (taking into account backwater and accumulation) shall be specified not less than 0.5 m, and not less than 1.0 m. for pressure or half-pressure pipes. Besides that, on highways in determination of superelevation of subgrade edge at the approaches to the said-above structures the requirements of SNiP 2.05.02-85 for superelevation of the pavement bottom above the level of ground and surface water shall be observed. Within ice action to the flood plain embankment the elevation of its edge should be not lower than elevations of accumulated ice top, and also elevations of maximum ice dam or jamming, taking into consideration one and a half thickness of ice. Backwater on bridge crossings is determined by liquid motion equations or by dependencies that quite enough take into consideration these phenomena on designed crossings.

SNiP 2.05.03-84 Page 13

DESIGN OF CARRYING STRUCTURES AND FOUNDATIONS OF BRIDGES AND CULVERTS FOR ACTION OF FORCES

GENERAL INSTRUCTIONS 1.35. Carrying structures and foundations of bridges and culverts shall be calculated for action of dead loads and unfavourable combinations of live loads described in Section 2. The designs shall be performed as per the limit states, subject to the requirements ST SEV 384-76.

1.36. *Live loads of rolling stock of the railway roads (locomotives and vans) and of the highways (cars, trucks, trailers and two-wheel trailers) in cases provided by existing regulations shall be introduced into calculations with the corresponding dynamic coefficients. If the effect of two or more live loads to the structure is considered simultaneously the designed value of these loads is to be multiplied to the coefficients of combinations, less or equal to a unity.

1.37. Structural models and main criteria of design should include actual behaviour conditions for structures of bridges and culverts during their operation and when they are under construction. Bridge span structures shall be designed, generally, as space structures, but when they are conventionally separated to flat systems they shall be designed by approximate methods established in the designing practice and shall specify member interrelation between each other and with the foundation. Forces in members of structures of bridges and culverts, for which the norms don’t indicate the methods of their calculation including originating inelastic deflections, can be determined on the assumption of elastic behaviour of the adopted structural model. With relevant grounds the design can be performed by deflected model that takes into consideration the action of shears of the structure under the load. Selection of structural models and design methods for bridges and culverts shall be performed with maximum use of computers.

1.38. Stress (strains) values determined in members of the structure when designed the structure at stage of operation and during the construction as well as stress (strains) values determined in assembling members or units by designs during their fabrication, transportation, and erection should not exceed the rated resistances (ultimate strains) established in norms of designing the corresponding structures of bridges and culverts.

1.39. Mean ambient air temperature of the most cold five days in the region of construction shall be specified as the rated minimum temperature, in conformity with the requirements of SNiP 2.01.01-82, with probability: 0.92 - for concrete and reinforced concrete structures, 0.98 - for steel structures and steel parts of steel-and-reinforced concrete structures.

1.40. *. Structure stability against overturning shall be calculated as follows:

where Mu - a moment of overturning forces relative to probable structure turning (overturning) axis going on end points of supporting;

Mz - a moment of confining forces relative to the same axis; m - a coefficient of behaviour conditions taken equal to: when checking the structures supporting to separate piers: 0.95 at stage of construction; 1.0 at stage of continuous operation; when checking the sections of concrete structures and foundations: 0.9 on rock bases; 0.8 on non-rock bases.

)1(zn

u MmMγ

≤

SNiP 2.05.03-84 Page 14

γn - a purpose reliability coefficient taken equal to 1.1 when performed calculations at stage of continuous operation and 1.0 - when performed calculations at stage of construction. Overturning forces should be accepted with a load reliability coefficient more than a unity. Confining forces should be accepted with a load reliability coefficient: γf < 1 for dead loads; γf = 1 for live vertical movable load from the train with empty cars of railway, underground railway and the tram. In appropriate cases following the instructions of item 7.6* it is necessary to specify the structure weight decrease due to buoyant action of water.

1.41. *. Stability of the structure against shear (sliding) shall be determined as follows:

where Qr - shearing force equal to the sum of shearing force projections on probable shift direction; Qz - confining force equal to the sum of confining force projections on probable shear direction; m - a coefficient of behaviour conditions specified equal to 0.9; γn - refer to item 1.40*. Shearing forces shall be accepted with the load safety factors equaled more than a unity, but confining forces shall be accepted with the load safety factors equaled as indicated in item 1.40*. Notes. 1. The force, which value doesn’t exceed the soil active pressure, can be accepted in a function of a confining horizontal force created by soil. 2. Friction forces in the base are determined by the friction coefficients specified in the item 7.14. At this, the coefficient of friction of concrete masonry to masonry shall be specified equal to 0.55.

STRAINS, DISPLACEMENTS, LONGITUDINAL SECTION OF STRUCTURES 1.42. Designing of bridges should ensure the smooth traffic through the bridge by means of constraint of the elastic deflections of superstructure under a movable live vertical load and by acceptance of the corresponding outline for in-line profile of a route or roadway part.

1.43. Vertical elastic deflections of superstructures calculated when moving live vertical load (at γƒ=1 and a dynamic coefficient 1+μ=1) acts should not exceed the values, m: for railway bridges - determined by formula

but not more than

for city and highway bridges (including bridges on internal economy roads and industrial enterprises roads), as well as for pedestrian bridges with girder superstructures -

where l is a designed span, m. The mentioned deflection values for girder superstructures (except a pedestrian bridge) are permitted to increase : - by 20% for single-span and continuous girder (except extreme spans of superstructure of railway bridges, supported onto intermediate piers);

)2('zn

r QmQγ

≤

ll25.1800

1−

;6001 l

,4001 l

SNiP 2.05.03-84 Page 15

- by 50% for wooden superstructures.

1.44. Required outline of the rail track and pavement of the roadway shall be designed by means of: a camber of superstructure; change of the regulating course depth of the roadway and of the ballast; effective depth of bridge bars. The camber of girder superstructures of railway bridges as well as of steel, composite and timber superstructures of highway and city bridges should be provided on smooth curve the arrow of which, after calculating the deflection of dead load, equals to 40% of elastic deflection of superstructure under moving live vertical load (at γƒ =1 and 1+μ =1). Pedestrian bridge superstructure camber shall be designed as to compensate the superstructure vertical deflections under dead loads. At this, the load safety factor is specified equal to a unity. Note. The camber can not be provided for superstructures which deflection under dead and moving live vertical loads doesn’t exceed 1/1600 value of a span (but not more than 1.5 cm in the half-through bridge) as well as for timber bridges with beams.

1.45. The camber and surface profile of reinforced concrete superstructures of highway and city bridges shall be provided in such a way that after appearance of strains caused by creep and shrinkage of concrete (but not later than 2 years since the action of full continuous load) the angles of change of longitudinal profile on axes of the traffic lanes in places of connection of span to span and to the approaches didn’t exceed: the values given in Table 4* when a bridge is not loaded with moving live vertical load; 24 ‰ for load AK and 13 ‰ for loads HK-80 and HГ-60, when a bridge is loaded with moving live vertical load on axes of the traffic lanes. Longitudinal profile of roadway shall be shown in design documents at the moment of arrangement of roadway pavement (with subsequent improvement of its outline by means of changing the regulating course depth) and after appearance of concrete creep and shrinkage deformations. Notes: 1. Before long deformations appearance the angles of change of longitudinal profile in absence of moving live vertical load on the bridge can exceed the values indicated in Table 4* not more than 2 times. In case of application of twisted wire ropes in cable-stayed and suspension bridges the possible wire rope creep strain shall be taken into consideration when specified the camber and the profile.

Table 4 Design speed of single cars on road sections adjoining to the bridge (in conformity with requirements of SNiP 2.05.02-85, SNiP 2.05.11-83), km/h

Angle of change, ‰

150-100 8 80 9 70 11 60 13 40 17

Notes. 1. If distance between span to span connection or to the approaches exceed 50 m,

the limit values of angle of change can be increased 1.2 times. 2. In temperature-continuous spans structures integrated by floor slab the angles of

change of profile shall be determined ignoring the influence of the joint plate.

1.46. In designing the superstructures of outside statically indeterminate systems the calculations should take into consideration possible settlements and displacements of the pier top. Horizontal and vertical displacements of the pier top shall be also taken into consideration, when determined the structures of bearing parts and expansion joints, dimensions of masonry plates (pier heads, cross-bars).

1.47. Different by value settlements of neighbouring piers should not cause in longitudinal profile the additional angles of change, exceeding:

SNiP 2.05.03-84 Page 16

2‰ - for motor road and city bridges; 1‰ - for railway bridges. Limit values of longitudinal and transverse displacements of piers tops of railway plate-girder bridges, taking into consideration the total river-bed scour, should not, as a rule, exceed a value 0.5 √lo cm, where lo is a length of the lesser span adjoining to a span pier specified not less than 25 m.

1.48. *.Design period of own transverse horizontal vibrations for plate-girder steel and composite superstructures of railway bridges should be (in seconds) not more than 0.01 l (l is a span in m) and should not exceed 1.5 s. In superstructures of pedestrian and city bridges the design periods of own vibrations (in unloaded state) on two lowest forms (in plate-girder system - on one lowest form) should not be from 0.45 to 0.60 s in vertical plane and from 0.9 to 1.2 s in horizontal plane. At this, for pedestrian bridge superstructures it is necessary to take into account possible crowding with people creating a load 0.49 kPa (50 kgf/m2). Periods of own transverse vibrations in vertical and horizontal planes should not exceed 3.0 s and a period of own torque at this should not exceed 2.0 s for cantilevers formed during cantilever erection or during incremental launching in the erection stage. Deviations from mentioned requirements can be allowed after making the corresponding calculations or special aerodynamic investigations on determination of stability and spatial rigidity of cantilevers to be assembled. At this, the requirements of item 2.24* on design of structure for action of wind pressure shall be kept. Cable-stayed and suspension bridges shall be checked for aerodynamic stability and spatial rigidity. Structures which dynamic characteristics differ to a great extent from analogous characteristics of existing bridges shall be tested, besides analytical analyse, on the models in a proper way.

1.49. When an embankment is higher than 12 m, a camber of culverts shall be specified in conformity with a calculation of assumed settlements under the embankment soil weight. Methods of calculating the settlements for foundations can be used to calculate settlement of culverts. When the embankments are 12 m high and less, culverts should be laid with a camber (as per gutter) equal to: 1/80 h - when foundations are on sand, pebble and gravel soils of the base; 1/50 h - when foundations are on clay, loam and sandy loam soils of the base; and 1/40 h - on soil pads from sandy gravel or sand-crushed stone mix (h - height of an embankment). Gutter elevations of input head (or input link) of the culvert shall be positioned in such a way that they are above the elevations of the middle link of the culvert both before the appearance of settlements of the base and after cessation of these settlements. Stability of design position of foundation sections and of culvert links in direction of longitudinal axis of the structure shall be provided by stability of the embankment slopes and by strength of soils in the base. Note. Culverts arranged on rocks and on pile foundations don’t require to specify a camber.

TRACK STRUCTURE OF RAILWAY BRIDGES 1.50. *.Track on reinforced concrete superstructure shall be laid on crushed stone ballast. Bridge road of steel superstructures shall be arranged, as a rule, on ballastless reinforced concrete slabs or on the ballast. With approval of the Ministry of Communications the arrangement of the track on timber sleepers can be applied on the steel superstructure bridges under construction. Rails on the bridges should be of heavy type (not easier than type P50 and not easier than type of rails laid on the approaches). On large bridges, on bridges with movable spans and at the approaches to these structures at a length not less than 200 m to each side the rails not easier than type P65 shall be laid. Continuous track can be laid on bridges with a bridge road on the ballast, on the bridges with ballastless bridge road - as a rule, when total length of span structures is 66 m and less. Continuous track can be laid on bridges with ballastless bridge road with span structures total length more than 66m in reasonable cases and with approval of the Ministry of Communications.

1.51. The bridge road structure should provide:

SNiP 2.05.03-84 Page 17

- a possibility for moving train wheels to run in case of losing the track; - maintenance and repair of track using the mechanized equipment

1.52. The ballast pocket of the abutments and superstructures with a ballast-base road should provide an arrangement of the ballast prism of typical cross section adopted for the bridges.

1.53. The bridge road (including guard sleepers, regulating devices or season regulating rails) shall be designed following the “Instructions on Arrangement and Construction of Bridge Road on the Railway Bridges” approved by the Ministry of Communications.

1.54. Ballastless bridge road on the reinforced concrete slabs should be not less than 3.20 m wide.

1.55. Bridge bars (timber bridge sleepers) should conform to GOST 8486-66, with section 20x24 cm and 3.25 m long.

1.56. *. Bridges of total length more than 25 m, as well as all bridges higher than 3 m, and bridges located within the railway stations, and all overpasses should be fitted with service footways both sides including the railings (not less than 1.10 m high) constructed outside the clearance to obstructions. In regions with daily mean temperature of ambient air -40°C and lower (with probability 0.92) all bridges of total length more than 10 m shall be fitted with sidewalks both sides. Besides that, double-track and multi-track bridges shall provide the sidewalks (without railings) on the inter-track. The sidewalk floor shall be made, as a rule, of the reinforced concrete slabs.

1.57. When designed the tracks on the approaches it is necessary to provide measures against displacement of a track from approaches to bridge.

1.58. *. On common network tracks and industrial railways located under the overpasses and pedestrian bridges with leg-type supports, at a distance from railway track axis to the support face less than 3.0 m, it is necessary to lay the safety angle bars protruding to each side of the lateral faces of overpass or pedestrian bridge not less than 10 m. Track on bridges and overpasses of industrial enterprise roads with curves of radius 500 m and less should be fitted with special devices preventing a change of the track gauge.

BRIDGE ROAD OF HIGHWAY AND CITY BRIDGES 1.59. * Bridge road parameters and construction should fit the requirements specified for this highway or street in SNiP 2.05.02-85, SNiP 2.07.01-89* or SNiP 2.05.11-83, and provide the mechanically arranged pavement and convenient conditions for running maintenance (mechanized cleaning of roadway floor and sidewalks from mud, snow, etc.).

1.60. *. Supports of lighting system and auxiliaries shall be positioned, as a rule, in the section line of railings (with sidewalk width 2.25 m and less) or in the inter-track of car tracks when they are set on the separate bed. Rail heads of car tracks on non-separate bed shall be installed from the side of traffic at a level of the roadway surface top. The city and pedestrian bridges, as a rule, should provide stationary electric lighting. On other bridges the necessity and the type of lighting are specified in conformity with the requirements of SNiP 2.05.02-85 and SNiP 2.05.07-85 for lighting system of the highways of different purpose.

1.61. *. Roadway floor pavement on reinforced concrete slab of roadway can be taken as a multi-course one comprising, as a rule, the surface, the protective coating, waterproofing and the regulating course, or it can be taken as a double- or single-course, comprising the regulating course of very low permeability concrete (as per SNiP 2.03.11-85 with water permeability class W8), performing waterproofing functions, and the asphalt-concrete surface, or comprising only the regulating course. Pavement of the roadway shall be provided in two courses of asphalt concrete of total thickness 70 mm of fine-grained mix in accordance with category of a road - type Б, В, and Г, not less than grade II, or of reinforced cement concrete of thickness not less than 80 mm.

SNiP 2.05.03-84 Page 18

The protective coating shall be made of low-permeable reinforced concrete not less than 40 mm thick (as per SNiP 2.03.11-85 with water permeability class W6). During the construction of cement concrete surface it is allowed to combine functions of the surface and of the protective coating. The regulating course in the multi-course construction of pavement shall be made of a cement-sand mortar of not less than 30 mm thick or it can be made of asphalt concrete. Roadway floor single or double-course pavement with a regulating course of very low-permeable concrete performing the functions of waterproofing can be arranged on the superstructures having no prestressed reinforcement in the reinforced concrete slabs of the roadway, on the condition that tensile stresses acting in the upper fibres of the regulating course don’t exceed the bending tension rated resistances of concrete defined in conformity with GOST 10180-78*. The protective course value should be specified not less than 40 mm. Superstructure roads of category III-V, I-c, II-c, on the agreement with the Customer, can apply precast reinforced concrete slabs laid on the regulating course of cement sand, 30-50 mm thick as a temporary pavement of the roadway floor. At this, the roadway slab and side surfaces of carrying structures where water can penetrate shall be waterproofed.

1.62. *. In pavement structures of roadway floor on steel plate of the roadway it is necessary to provide the measures to ensure trouble-free surface-to-steel bond and anticorrosion.

1.63. . Safety strips and dividing strips shall be distinguished by covering with different texture materials or by marking with continuous marking line of wear-resistant materials.

1.64. *. Bridges, as a rule, should provide a sidewalk on each side or servicing ways protected with railings 1.10 m high from outside. On bridges with separate span structures the sidewalks and servicing ways can be provided only from outside (relative to road axis) of each span structure. On city trestles, overpasses and bridges of truck roads separated from pedestrian traffic as well as on bridges of highways with pedestrian traffic volume 200 men/daily and less, it is allowed to provide the servicing ways only. Outside the populated areas when there is no pedestrian traffic on the bridges 50 m long, the servicing ways can not be arranged. Servicing way width is taken equal to 0.75 m. The sidewalk width shall be specified by calculation depending on a value of designed perspective traffic intensity of pedestrians for “hot” hour. Designed capacity of pedestrian lane of 0.75 m wide shall be specified equal to 1500 men/hour. Specified width of multilane sidewalks, as a rule, should be divisible by 0.75 m and of single lane sidewalk, not less than 1.0 m. On bridges located in cities, villages and rural populated areas the sidewalks shall be specified not less than 1.50 m wide. Sidewalks of width not divisible by 0.75 m stipulated by constructional considerations can be allowed in availability of corresponding feasibility study and approval of the Customer.

1.65. * From the side of traffic the sidewalks and separate car tracks on highways, and arterial streets and roads should be separated from the roadway part by means of crash barriers: - steel guard railings or reinforced concrete parapets 0.75 m high on bridge structures of highways of category I-III and in cities; - ditto, 05 m high on bridge structures of highways of category IV, V, I-c, in villages and rural populated areas; - wheel guard 0.25 m on timber bridges. Height from the top of road surface to the upper face of the crash barrier shall be accepted as a height of the crash barrier. Crash barrier height on bridge structures of industrial enterprises roads shall be specified not less than ½ of the equivalent car wheel diameter, but not less than 0.75 m.

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In case bridge structures has no sidewalks and servicing ways the crash barriers can be installed not close than 0.5 m from the edge of the span slab and at this they can coincide with railings that should be installed in all cases. Median crash barriers shall be provided in case if: - there are crash barriers on the median lane of approaches; - the median lane bears the members of the bridge structure, supports of auxiliaries, lighting system, etc.; - the median lane structure is not designed for vehicles to enter the lane. Crash barriers at approaches to the bridge structures shall be installed at a length not less than 18 m from the beginning and the ending of the structure, at this, the first 6 m of crash barriers should be installed in the same section line as crash barriers of the bridge. Taper for crash barriers installed on the bridge structure to the crash barriers on shoulders of the road should be with tangent not more than 1:20.

1.66. *. Expansion joint structure should not disturb a smooth traffic of vehicles and should avoid penetration of water and dirt to bearing areas and down-located parts of the bridge. In case of water permeable joints it is necessary to provide a possibility to inspect and to repair the joints from the top, removal of water penetrating through the joint with the help of chutes with a slope not less than 50‰, easy inspection and cleaning the chutes from mud. Cement concrete surfaces above the expansion joints shall not be solid in all cases. Asphalt cement surfaces can be continuous on the roads of category I-III, I-c, I-в, I-к,II-к with displacements in the joint not more than 5 mm, and on the roads of lower category up to 10 mm. Expansion joint structures shall be safely fixed in superstructures. Overlap elements, sliding sheets or plates should be fit tightly to a border with the help of springs and other means, excluding a loose fitting of overlapping slide members.

CONNECTION OF BRIDGE TO APPROACHES 1.67. . Near the large railway bridges a subgrade at a length of 10 m from the back side of abutments shall be widened by 0.5 m each side; near the highway and city bridges it should be wide not less than a spacing between the railings plus 0.5 m each side. The enlarged width shall be smoothly tapered to the normal one at a length 15-25 m.

1.68. . In place of connecting the embankment to the abutments of railway bridges the measures preventing the ballast prism sliding shall be provided.

1.69. *. Transition reinforced concrete slabs shall be installed, as a rule, in place of connection of highways and city bridges to the embankment. The slab length shall be determined depending upon the assumed settlement of soil under sole piece of the slab and shall be specified, as a rule, not more than 8 m. On bridges with abutments bearing directly onto the embankment (sofa type) the transition slabs length shall be specified taking into consideration the keeping of road profile with possible different settlements of bearing areas of the slabs and shall be taken not less than 2m. Sandy gravel bedding under the slab sole piece should support its whole area against filtering soil or embankment soil below the depth of frost penetration. With soft clay in the base of an embankment the transition slabs sole pieces shall be laid with assumption of their possible settlement in the rate 05-07 % of the embankment height.

1.70. . In connecting the bridge structures to the filled approaches the following requirements should be observed: a) Having settled the embankment and the cone, the embankment-adjoining part of abutment or free cantilever (in highway bridges) should enter the cone for a value (defining from the vertex of a cone at a level of top of slope to the face connected to the embankment of the structure) not less than 0.75 m when embankment is up to 6 m high, and not less than 1.00 m when embankment is above 6 m high.

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b) Cone slopes should go below the bridge seat (in plane of cabinet wall) or top of side walls enclosed the cabinet part not less than 0.50 m for the railway bridges and 0.40 m for the highway and city bridges. The cone foot at non-retaining-type abutments should not protrude over the front face of the abutment. In retaining-type abutments of bridges the line of intersection of cone surface and front face of the abutment should be located above water level of designed flood (without backwater and wave run) not less than 0.50 m above c) Cone slopes of nonretaining-type abutments of bridges should have gradients not steeper than 1:1.25 on a height of the first 6 m, starting to measure from top of slope and not steeper than 1:1.50 on a height of next 6 m. The steepness of cone slopes of embankments over 12m high shall be determined by calculation of cone stability (with checking the base) and specified not less than 1:1.75 within a whole cone or up to its more gentle part. d) Cone slopes of retaining-type abutments, abutments of frame bridge, pile-trestle bridge and also of all bridges within underflooding at water level of design flood should have grade not steeper than 1:1.5; when the embankment is more than 12 m high slopes shall be determined by calculation of stability (with checking the base). For seismic areas the cone grades shall be specified in conformity with the requirements of SNiP II-7-81*.

1.71. The last row of supports or piles of timber bridge abutments should enter the embankment not less than 0.50 m, starting from axis of support to top of the cone, at this, the ends of the stringers shall be protected against contact with the soil.

1.72. *. The cones near the bridges as well as the embankments after the bridge abutments shall be filled up with sand or other filtering soil with a filtration coefficient (after compaction) not less than 2 m/daily for a length at the top not less than a height of the embankment after the abutment plus 2.0 m and close to the ground (in level of natural soil surface) not less than 2.0 m. In special cases in availability of feasibility study it is allowed to use sands with a filtration coefficient less than 2 m/daily, provided that with the help of structural and technical measures (including the use of strengthening and reinforcing synthetic materials and meshes) the proper reliability and durability of abutments, cones and embankments behind the abutments will be guaranteed.

1.73. . The cone slopes near the bridges and underpasses shall be strengthened for full height. Types of strengthening of the slopes and footings of the cones and embankments within underflooding at the approaches to the bridges and near the culverts and also of the slopes of the regulating works shall be specified depending upon their steepness, conditions of ice gang, action of waves and water stream with speeds corresponding to the maximum flows during the floods: the largest one for the bridges of the common network railways and the designed one for other bridges. Elevations of the strengthening top shall be higher than water levels corresponding to the mentioned above floods taking into consideration the backwater and wave setup to the embankment: not less than 0.50 m near the large and middle bridges; not less than 0.25 m near the small bridges and culverts.

WATER DIVERSION 1.74. Roadway floor and other surfaces of the structures (including under the sidewalks), where water can penetrate, shall be designed with a cross grade not less than 20 ‰, and in railway bridge ballast pockets , not less than 30‰. The longitudinal grade of roadway floor surface on the highway and city bridges shall be specified, as a rule, not less than 5‰. The longitudinal grade more than 10‰ allows to decrease the cross grade on condition that vector sum of the grades will be not less than 20‰. Railway bridges on the asbestos ballast should provide the surface water removal.

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1.75. *Water from roadway floor shall be removed through small drain pipes or through transverse or longitudinal gutters. If the roadway floor pavement construction includes waterproofing (except waterproofing of very low permeability concrete), the small drain pipes shall be installed in any case. Non-organised spill through the sidewalks (all over the entire length of the deck structure) is prohibited. Top of small drain pipes and bottom of gutters should be arranged not less than 1 cm lower the surface from which water drains. Water from drain devices should not enter the down-laid structures and also the railway tracks and roadway of highways located under the overpasses. To prevent regular moistening of the lower surfaces of the reinforced concrete and concrete structures (cantilever slabs of end beams, sidewalks, heads of the supports, etc.) it is necessary to arrange the protective projections and drips. Places of water spill from the deck to the embankment cone shall be equipped with water drain chutes. To remove water from behind the abutments it is necessary to arrange good drainage system.

1.76. *The water drain pipes should have the inner diameter not less than 150 mm, and they should be installed in ballast pockets of railway bridges at a rate not less than 5 cm2 of pipe section as per 1 m2 of drain area. A distance between water drain pipes on the roadway floor of highway and city bridges should be along the span structure not more than 6 m at longitudinal grade up to 5‰ and 12 m at grades from 5 to 10 ‰. With more steep grades a distance between drain pipes can be increased. Pipes should be not less than three in number on one span.

1.77. Within closed sections (under members of roadway floor pavement and in other places where accumulation of randomly penetrated water as well as water accumulated due to condensation of atmospheric moisture can happened) it is necessary to provide an installation of drain pipes (or holes) not less than 60 mm in dia in the lowered places. Removal of water out of cavities under sidewalk slabs shall be arranged, as a rule, without application of small drain pipes.

1.78. When it is necessary to preserve everfrozen soil, the foundation of abutments should provide protection against water penetration to the foundation. In case of surface-water coming from the side of approaches it is necessary to arrange removal of it beyond the subgrade.

OPERATIONAL PARTS 1.79. *All parts of span structures, visible surfaces of supports and culverts shall have an access for inspection and maintenance, for this purpose there should be arranged passages, hatches, stairs, handrails (not less than 1.10 m high), special manholes as well as embedding parts to hang temporary scaffolds. The bridges with beam span structures and movable bearing parts should provide the conditions to carry out position regulating work, repair work or replacement of the bearing parts.

1.80. Each end of the bridge or culvert on an embankment more than 2 m high for railways and more than 4 m high for highways shall be fitted, as a rule, with permanent stairs 0.75 m wide arranged on slopes.

1.81. *Design documents when necessary (for ex. in construction of bridges and culverts in the course of the experience, in application of statically indeterminate systems sensitive to precipitation, in creating a pre-stressed state in steel structures, etc.) should provide the installation of special marks or other devices which are necessary to keep control for general strains and stressed states of separate elements as well.

1.82. *Railway bridges and underpasses of tunnel type at their length more than 50 m should provide shelter grounds every 50 m staggered in the level of railway passage both sides. With a length of the bridge or underpass up to 100 m the shelter grounds can be arranged by one each side of the passage.

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On lines where a train speed is provided more than 120 km/h as well as on bridges in the regions with average ambient air temperature of the most cold five days minus 40°C with probability 0.98, a distance between shelter grounds should be not more than 25 m.

1.83. Railway bridge fire-fighting equipment should conform to Instructions on arrangement and design of bridge road, established by Ministry of Communications; highway bridge fire-fighting equipment should conform to a list approved by Ministries of Motor Road Communications of the Union Republics.

1.84. All steelworks of the bridges shall be grounded if they are located at a distance less than 5 m from overhead of direct current and less than 10 m from overhead of alternating current. Reinforced concrete and concrete structures supporting the overhead shall be grounded as well.

1.85. Designing of overpasses and footway bridges through the electrified railways should provide above the overhead the installation of fences and vertical guards (nets) 2 m high. Horizontal guards (nets) not less than 1.5 m long can be used.

1.86. Railway bridges and overpasses through the tracks delivering ladles with hot metal and hot slag should have special guard railings instead of handrails, which height should be 20 cm higher than the top of ladles. At this, shelter grounds in staggered arrangement shall be provided every 50 m both sides. Overpass designs under which ingot cars, hot-metal or hot slag cars are supposed to pass should have special screens which limit the heating of guarded structures to a temperature not higher than 100°C. 1.87. *On all bridges it is prohibited to lay out the oil pipelines, oil product pipelines and, as a rule, high voltage power transmission lines (of voltage higher than 1000 V). Besides that, on the railway bridges it is prohibited to lay out the gas pipelines, sewerage pipelines and water supply lines as well. With availability of special feasibility study the highway, city and footway bridges can bear heating network, water supply pipelines, pressure sewerage pipeline and gas pipelines with working pressure not more than 0.6 MPa (6 kgf/cm2), all of them in steel pipes. All cases should provide measures to ensure the bridge integrity as well as its safety traffic motion without interruption in situation when pipelines or cables happen to break or damage. For this purpose large and middle-sized bridges electrical lines and other communications, as a rule, and railway bridges ones without fail should be fitted with the equipment to disconnect such lines and communications from both sides of the bridge. Note: In reasonable cases with the approval of the operative authorities or the customer the cable lines of high voltage power transmission lines can be installed on city and highway bridges located in the populated areas on the condition of ensuring the safety maintenance of the bridge. Local laying of cable oil-filled lines and high voltage power transmission lines is prohibited.

1.88. *.Bridges shall be fitted with devices to pass over the communication lines of road and other utility lines that can be installed on the given structure and bridges on the railways (including lines where electric traction for train is not initially provided) and trolley-buses and trams traffic ways in the city shall be fitted with devices for hanging the contact system. The installation of pipes and cables should provide, as a rule, special structural members (outside cantilever beam, transverse diaphragms, outer hangers, etc.), not preventing the execution of work on current maintenance and repair of the bridge. Utility lines under sidewalk slabs and on the median lane can be laid with protection of both utility lines and bridge structure against a damage during the operation. Installing of utility lines in closed cavities of blocks under sidewalk slabs requires an arrangement of waterproofing and holes for water removal.

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1.89. Railway and highway bridges with movable spans as well as bridges with a combined roadway (for not simultaneous traffic of rail and not-rail transport) shall be guarded both sides with holding signals located at a distance not less than 50 m from entering them. For city bridges the distance from entrance to holding signals is established on approval with State Road Inspection of Ministry of Inner Affairs. Holding signals should be open only when the movable span is in its close position, and when the combined roadway is free. Railway bridges with movable spans as well as one-way bridges on two-way sections of the road shall be protected with safety (catching) dead ends or with obstacle device. Large railway bridges shall be equipped with protection-and-indication signalling as well as with monitoring-and-clearance devices in conformity with Technical Operation Instructions for Railways established by the Ministry of Communications. Navigation spans of the bridges through the water ways shall be equipped with navigation signal lights.

1.90. Guarded bridges shall be equipped with guard post houses and corresponding equipment. Near the large railway bridges as well as highway and city bridges with a length more than 200 m it is necessary to provide the servicing house with area 14-25 m2 and besides that, in reasonable cases the house for compressor installation. On the large railway bridges with an approval of the Ministry of Communications, it is necessary to provide the lines for supply the compressed air and water, as well as lines for longitudinal electric power supply with current collecting points to mechanise current maintenance and repair work.

2) LOADS AND FORCES COMBINATIONS OF LOADS

2.1. *Bridge and culvert structures shall be designed for the loads and forces as well as for combinations of loads that are specified in accordance with Table 5*.

2.2. Load combination coefficients η taking into account a decrease of probability for simultaneous occurrence of design loads shall be specified in all calculations equal to:

a) 1.0 – to dead loads Nos 1-6, to the load No.17 and to the weight of train with empty cars. b) 1.0 – when the action of only one of the live loads Nos. 7-9 or group of loads

accompanying each other without other loads is taken into account; c) 0.8 - to one of the live loads and 0.7 - to other loads when the action of two or more live

loads (conventionally considering the group of loads Nos 7-9 as one load) is taken into account.

Notes: 1. To the load No.12 in all cases of combination with the load No.7 depending upon the type of moving vehicles that create a load the coefficient η shall be taken equal to:

a) when loaded with railway moving train and with subway moving trains : exposed to action of side wind - 0.5; protected with galleries against action of side wind - 1.0;

b) when loaded with highway moving vehicles and with the tram cars – 0.25. For highway and city bridges in case of action of several live loads and in absence of the load No.7 among them, the coefficient η = 0.5 shall be taken to the load No.12. 2. In all load combinations the coefficient η shall be taken the same to loads Nos.7-9, and to the load No.11 not more than the coefficient of the load No.7. 3. With consideration of the load No.18 together with the load No.7 and accompanying to it, the coefficients η shall be specified 0.8 to the load No.18 and to other live loads: for railway bridges (only of one track) – 0.7; for highway and city bridges – 0.3. 4. Values of coefficient η for different combinations of live loads and forces are given in Reference Appendix No.2.

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2.3. The load and force values for designing the structures in all groups of limit states are specified in accordance with Table 6 with the load safety factor γf (as per items 2.10*, 2.23* and 2.32* for corresponding characteristic loads and forces) and with dynamic coefficients 1+µ or 1+ 2/3µ (as per item 2.22*).

Table 5* Number of load (force)

L o a d s a n d F o r c e s Number of load (force) not considered in combination with given load (force)

1 2..

Dead Dead weight of the structure Initial stress (including regulation of forces )

- -

3 Earth pressure from embankment weight - 4 Hydrostatic pressure - 5 Creep and shrinkage of concrete - 6 Earth settlement - B. Live loads of moving vehicles and pedestrians 7 Vertical loads 16, 17 8 Earth pressure from moving vehicles 16, 17 9 Horizontal transverse load from centrifugal force 10, 16, 17 10 Horizontal transverse impacts of moving vehicles 9, 11, 12, 16-18 11 Horizontal longitudinal load from brake or traction force 10, 13, 14, 16,

17 Others 12 Wind load 10, 14, 16 13 Ice pressure 11, 14 14 Vessels impact 11-13, 15-18 15 Temperature, climate effect 14, 18 16 Effect of soil frost heaving 7-11, 13, 14, 18 17 Construction load 7-11 18 Earthquake loading 10, 12-17

Notes. 1* When necessary, calculations should include friction and shear resistance in bearing parts, classified as other forces. 2. Endurance shall be designed for combinations that include besides dead loads and forces the loads Nos 7-9, at this the vertical load of pedestrians on sidewalks shall not be considered together with the vertical load of moving vehicles. 3* The limit states of group II shall be designed only for combination of loads and forces Nos 1-9, 15 and 17. At this, the reinforced concrete structures crack resistance computation shall also include the load No. 11, and in case of computing the pier top horizontal displacements the loads Nos 10, 12 and 13 shall be considered.

Table 6 Factors introduced Group of

limit state

Kind of design to all loads and forces except moving vertical one

to moving vertical load*

I All designs except listed in sub-items «б»-«г» б As per durability в As per stability of position

γf γf = 1 γf

γf; 1+µ γf = 1; 1+2/3µ γf***

г As per combinations, - including the seismic load

γf**

γf

II All designs including ones as per formation and opening of the cracks in reinforced concrete

γf = 1 γf = 1

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In all unmentioned cases (except the load of cranes as per item 2.30) the dynamic coefficient 1+µ shall be taken equal to a unity. ** Seismic loads shall be taken with the load safety factor equal to a unity. *** For railway and subway train with empty cars the factor is specified as γf = 1.

DEAD LOADS AND FORCES 2.4 The characteristic vertical load of dead weight shall be determined by the designed quantities of members and parts of the structure, including all permanent inspection devices, poles and wires for electric and communication lines, pipelines, etc. The beam span structures can take the dead weight load equally distributed over the span length if its value on separate sections deviates from the average one not more than 10 %.

The characteristic load from the weight of bridge floor with one railway track shall be specified equal to: 6.9 kN/m (0.70 tf/m) of the track with wooden sleepers and without sidewalks; 12.7 kN/m (1.30 tf/m) of the track with wooden sleepers with two sidewalks fitted with steel brackets and reinforced concrete slabs of the floor; 16.7 kN/m (1.70 tf/m) of the track with reinforced concrete ballastless slabs without sidewalks; 22.6 kN/m (2.30 tf/m) of the track with reinforced concrete ballastless slabs with two sidewalks. The weight of weld joints as well as of protruded parts of high-tension bolts in complete with nuts and two washers can be specified in percents of the total steel weight as per Table 7.

Table 7

Steel structure Weld joints,

%

Protruded parts of high-tension bolts, nuts and two washers, %

Bolt-welded

Welded

1.0

2.0

4.0

-

2.4. Characteristic effect of prestress in the structure (including the regulation of forces) shall be determined by the specified (regulated) force taking into account the characteristic values of losses, corresponding to the performance stage under consideration. In reinforced concrete structures besides the losses connected with the technological process for prestress and regulation of forces it is also necessary to take into account the losses caused by shrinkage and creep of the concrete.

2.5. Characteristic soil pressure of the embankment mass onto the bridge piers and pipe links shall be determined by formulae, kPa (tf/m2), as follows: vertical pressure for bridge piers

for pipe links

horizontal (lateral) pressure

where h, hx - height of fill, m, determined for bridge abutments according to Compulsory

Appendix 3; for pipe links - according to Compulsory Appendix 4*;

)3(;hp nγν =

)4(;hCp nγνν =

)5(,nxnn hp τγ=

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γn - characteristic specific weight of soil, kN/m3 (tf/m3);

Cv - vertical pressure coefficient determined for pipe links according to Compulsory Appendix 4*;

τn coefficient of characteristic lateral pressure of soil for filling the bridge abutments or pipe links, determined by the following formula

here ϕn - characteristic angle of soil internal friction, in °. The values γn , ϕn shall be based, as a rule, on laboratory study of samples of soil intended to be used for the filling of the structure. In typical designing for determination of characteristic pressure of soil it can be accepted the specific weight of fill soil γn = 17.7 rN/m3 (1.80 tf/m3), and characteristic angles of internal friction ϕn equal to : 35° for abutments when sand (filtering) soil is used to fill; 30° for pipe links located inside the embankment; 25° for heads of pipes. Methods of determining the resultant of characteristic horizontal (lateral) pressure onto the bridge piers from the dead weight of soil are described in Compulsory Appendix 3.

2.6. Characteristic hydrostatic pressure (water buoyant effect) shall be determined according to the instructions of Section 7.

2.7. The concrete shrinkage and creep characteristic effect shall be considered as relative deformations and included when determined the displacements and forces in the structures. Creep of the concrete is determined only by the action of dead loads. Values of characteristic deformations of shrinkage and creep for the performance stage under consideration shall be determined by values of maximum relative deformations of shrinkage of concrete εn and specific deformations of creep of concrete cn in accordance with the instructions of Sections 3 and 5.

2.8. Characteristic effect of subsidence in foundation of the bridge piers shall be taken into consideration when using the span structures of statically indeterminate system and shall be specified by the results of foundation subsidence design.

2.9. The load safety factors γf for dead loads and forces, indicated in items 2.4-2.9 shall be specified as per Table 8*. In so doing, on all parts loaded with a load the values γf for each of the loads shall be specified as the same in all cases, except the computation of position stability where γf for different loaded parts is taken in accordance with items 1.40* and 1.41*.

Table 8* L o a d s a n d f o r c e s Load safety factor γf

All loads and forces except listed below in this Table 1.1 (0.9)

Weight of bridge road with ballast way for the railway track as well as the tracks for subway and the tram

1.3 (0.9)

Weight of ballast bridge road for tram tracks on the concrete and reinforced concrete slabs

1.2 (0.9)

Weight of regulating course, waterproofing and protective coating on highway and city bridges

1.3 (0.9)

)6(;)2

45(2 nn tg ϕ

τ −°=

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Weight of roadway floor and sidewalk surfacing of highway bridge 1.5 (0.9)

Ditto, of city bridges 2.0 (0.9)

Weight of timber structures of bridges 1.2 (0.9)

Soil horizontal pressure of the embankment weight:

onto the bridge piers (including abutments) 1.4 (0.7)

onto the pipe links 1.3 (0.8)

Action of shrinkage and creep of the concrete 1.1 (0.9)

Action of subsidence 1.5 (0.5)

Notes. 1. Values γf for bridges of intra-economy motor roads shall be specified the same as values for bridges of general-use highways. 2. Values γf indicated in Table 8* in brackets shall be specified in case when unfavorable combinations of loads increase their total effect to the members of the structure.

LIVE LOADS OF MOVING VEHICLES AND PEDESTRIANS 2.10. The characteristic live vertical load from railway moving train (CK) shall be specified (including the future development of railway transport) in the form of the envelope maximum equivalent loads ν, kN/m (tf/m), of the track received from separate groups of concentrated freights with weight up to 24.5K kN (2.50K tf) and uniformly distributed load of intensity 9.81K kN/m (1K tf/m) of the track. Index K indicates the class of established load that is taken equal to: 14 - for permanent structures; 10 - for timber bridges. The Table of characteristic load intensity ν and regulations of loading the influence line with the given load are described in Compulsory Appendix 5. At this, symbols are taken as follows: λ - loading length of influence line, m; α = α/λ - relative position of influence line peak; α - projection of the least distance from the line peak to the end, m. The weight loaded to 1 m of the track shall be taken equal to values ν with α =α/λ = 0.5, but not more than 19.62K kN/m (2Ktf/m) of the track. The vertical live load of the train with empty cars shall be taken equal to 13.7 kN/m (1.40 tf/m) of the track. The characteristic load for design of bridges and culverts on industrial enterprises tracks of railway with very heavy trains circulation shall be specified taking into account the weight of train. In cases shown below the load CK shall be introduced into computations with factors ε ≤1, that indicate the presence of perspective locomotives and cars only and the absence of heavy carriers. The load ε CK is required to include in computation : of durability; of reinforced concrete structures as per opening the cracks, as per seismic loads as well as when determined deflection of deck and displacement of supports - on all loaded tracks; when loaded the second and the third tracks – in all other cases. The factor ε value shall be determined as per Table 9.

Table 9 Length of loading λ , m 5 and less From 10 to 25 50 and more

Factor ε 1.00 0.85 1.00

For intermediate values λ the factors ε shall be determined by interpolation. Note. If besides the factor ε the design includes the dynamic coefficient (1+µ or 1+ 2/3 µ ), then their product shall not be taken less than a unity.

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2.11. *The characteristic vertical live load of moving vehicles on highways (of general purpose, intra-economy roads in kolkhoses and sovkhoses and other agricultural enterprises and organizations), on streets and roads of cities, villages and rural populated areas shall be specified (including the perspective) as follows: a) 0.98K kN/m (0.10K tf/m) from highway vehicles - in the form of lanes AK (dwg. 1, a), each lane includes one two-axle bogie with axial load P equal to 9.81K kN (1K tf), and uniformly distributed load of intensity ν (to both tracks) 1. The load AK is loaded also to the car tracks when they are located on the common bed. The load class K shall be specified equal to 11 for all bridges and culverts except of timber bridges on roads of category V and intra-economy roads of category II-c and III-c for which it can be specified equal to 8. The members of bridge roadway designed for load A8 shall be checked for one-axle pressure equal to 108 kN (11 tf) (dwg.1, б); b) from heavy single wheel and crawler transport loads (dwg.1, b): for bridges and culverts designed for the load A11 – in the form of wheeled load (one four-axle car) HK-80 of total weight 785 kN (80 tf); for bridges and culverts designed for the load A8 – in the form of the crawler transport load (one car) НГ-60 of total weight 588 kN (60 tf); c) of subway moving train from each track - in the form of the train of effective length, consisting of four-axle cars (dwg.1, г) each loaded car of total weight 588 kN (60tf). When loaded the influence line having two or more sections of the same sign, the separating sections of other sign shall be loaded with empty cars each of weight 294 kN (30tf); d) of trams (when car tracks are located on individual enclosed or detached bed) from each track - in the form of a train with four-axle cars (dwg.1, д) each loaded car of total weight 294 kN (30 tf) and of empty car – 147 kN (15 tf); number of cars in the train and distance between trains shall correspond to the most unfavorable loading limited as follows: number of cars in one train is not more than four; distance from next train relative to the end axles of trains is not less than 8.5 m. Loading of the bridge with mentioned loads shall create the maximum forces in designed members, maximum displacements (deformations). in places of structure defined by regulations. At this, for the load AK in all cases the conditions shall be observed as follows: in availability of the influence line having three or more sections of different signs a car is loaded to the section that gives for the sign under consideration the maximum value of force (displacement), the uniformly distributed load (with required interruptions by length) is loaded to all sections causing the force (displacement) of this sign; the number of load lanes disposed on the bridge should not exceed the accepted number of traffic lanes; distance between axes of adjacent lanes of load should be not less than 3.0 m; with multilane traffic in each direction and in absence of the dividing strip on the bridge the axis of left-hand (inner) lane of load of each direction should not be disposed closer than 1.5 m from the axial line or line dividing the traffic directions. When designed the bridge structures as per strength and stability it is required to consider two cases of action of the load AK: the first case considers unprofitable disposition on the roadway (excluding the safety strips) of load lane number not exceeding the number of traffic lanes; _____________ 1In all diagrams c is a length of touching the roadway with a tire. the second case considers with unloaded sidewalks the unprofitable disposition on the whole width of the roadway floor (including the safety strips) of two load lanes (on one-lane bridge – with one load lane). At this, the load AK end lanes axes shall be disposed not closer than 1.5 m apart the roadway edge in the first case, and apart the roadway crash barrier – in the second case.

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When computed the structure for endurance and as per limit states of the second group it is required to consider only the first case of the load AK action. When determined the combined action of several force factors in section under consideration the load AK can be positioned in the most unfavorable place for each factor. The bridges for subway tracks (uncombined), when designed as per limit states of the first group, shall be checked for loading of one of the tracks with a train not creating the dynamic force but having a length exceeding (up to twice) the length of the effective train. At this, on two-track bridges the second track shall be loaded with a train of effective length. Heavy single loads HK-80 and НГ-60 shall be disposed along the traffic direction on any section of the bridge roadway (excluding safety lanes); the equivalent loads for them are listed in Reference Appendix 6*. Notes. 1. If the bridge provides 3-m and more median not fitted with barriers then in loading the bridge with vertical live loads the possibility to use this median for traffic in future shall be taken into consideration. 2*. The loads HK-80 and НГ-60 are not taken into consideration in combination with the live load at sidewalks, with seismic loads, as well as when computed the structure for endurance. 3*. On roads of category V the large- and middle-sized bridges can be designed for the loads A8 and НГ-60 only in case of proper grounds and with the approval of the republic state construction authorities. 4. In loading the tram track with the live load of motor vehicles (item 2.12*a) the load AK lane axes should be matched to the tram track axes. 5. Distribution of pressure within the roadway pavement thickness shall be accepted at an angle 45°. Dwg. 1. Diagrams of loads from moving vehicles to design the highway and city bridges. motor vehicle load AK in the form of a line of uniformly distributed load of intensity ν and single car with pressure to the axle P; б- single axle for checking the roadway part of the bridges designed for load A-8; в- heavy single loads HK-80, НГ-60; г- subway trains; д- tram trains.

2.12. Moving vehicles characteristic vertical load on the industrial enterprise motor roads that provide the circulation of vehicles with very high load capacity and that have no limits in respect to weight and overall dimensions of general-purpose vehicles shall be specified in the form of a column of two-axle trucks АБ with parameters given in Table 10.

Table 10 Parameter L o a d s

АБ-51 АБ-74 АБ-151

Load to loaded truck axle,

kN (tf): rear

333 (34.0)

490 (50.0)

990 (101.0)

front 167 (17.0) 235 (24.0) 490 (50.0)

Distance between axles (base) of the truck, m

3.5 4.2 4.5

Overall dimension as per width (by rear axle wheels), m

3.5 3.8 5.4

Track width, m

Of rear wheels 2.4 2.5 3.75

Of front wheels 2.8 2.8 4.1

SNiP 2.05.03-84 Page 30

Ground of touching the rear wheels with roadway surface, m

by length 0.40 0.45 0.80

by width 1.10 1.30 1.65

Wheel diameter, m 1.5 1.8 2.5

The designing should consider the following cases: a) on the bridge there are moving the columns of cars creating dynamic action provided by the

present Building Code. b) on the bridge a forced stoppage of the designed cars takes place (no dynamic action )

In case (a) distance between rear and front axles of neighboring cars in each column should be not less than:

20 m for loads АБ-51 and АБ-74; 26 m for load АБ-151. As applied to the bridge width the trains of vehicles should not exceed a number of traffic lanes and shall be installed in the most unfavourable position keeping the distance indicated in Table 11. In case (b) the bridge is loaded with one train of vehicles consisting of not more than three cars. Distance between rear and front axles of neighboring cars should be not less than 8 m for loads АБ-51 and АБ-74 and not less than 10 m for load АБ-151. On other lanes it is placed not more than one car. As applied to the bridge width the train of vehicles and the single car are installed in the most unfavourable position keeping the distance indicated in Table 11.

Table 11.

Distance as per width of bridge

The minimum dimension, m

for loads

АБ-51 АБ-74 АБ-151

From crash barrier to the end of rear wheel of car :

moving 1.0 1.2 1.6

standing close to

Between ends of rear wheels of neighboring cars:

moving 1.9 2.0 2.5

standing 0.5 0.7 1.0

The equivalent loads for triangular influence lines from single cars of load АБ, as well as from standing and moving trains of these cars (with installed minimum distance between cars) are given in Reference Appendix 7. Note. Bridges and culverts located on industrial enterprises motor roads with circulation of vehicles of types MAZ and KrAZ with designed width above 2.5 m and with pressure of rear bogie less than 196 kN (120tf) shall be designed for the loads A-11 and HK-80.

2.13. In all calculations of bridge members or single structures that take the live load of several tracks or traffic lanes the load of moving vehicles of one track or one traffic lane (where the load leads to the most unfavourable results) shall be specified with the factor s1 = 1.0. The loads of other tracks (lanes) are taken with factors s1 equal to

a) for load ε CK (not more than three tracks are loaded simultaneously): 1.0 – when loading length is 15 m and less;

0.7 - when loading length is 25 m and more;

for intermediate values of length the factor is defined by interpolation;

SNiP 2.05.03-84 Page 31

b) for load AK: 1.0 - for bogies and 0.6 - for uniformly distributed load;

c) for load AБ - 0.7; d) for subway trains and the tram - 1.0.

2.14. When motor traffic lanes (together with sidewalks) and rail tracks (of the railways, subway or the tram) the vertical live load that produces less force ( both vertical and horizontal) shall be introduced into calculation with an additional factor s2 determined by the following formulae: with simultaneous loading of railway tracks and motor traffic lanes s2 = 1 – 0.010 λ, but not less than 0.75, (7) ditto, of the tracks of subway or the tram and of motor traffic lanes s2 = 1 – 0.002 λ, but not less than 0.75. (8) where λ - length of loading the deck with a load producing the less force, in m

2.15. Characteristic horizontal (lateral) pressure of soil on to the bridge abutments (and intermediate piers if they are located inside the cones) from the moving vehicles standing on the sliding triangle shall be specified taking into consideration the distribution of the load in soil below the rail foot or at the top of the road surface at an angle to vertical arc tg ½ and determined according to the Compulsory Appendix 8*. Note. In combination with the seismic load the horizontal (lateral) pressure of soil on to the abutments from the moving vehicles standing on the sliding triangle is not considered. Characteristic pressure of soil from moving vehicles on to the pipe links (sections), kPa (tf/m2), on the corresponding projection of outside contour of the pipe shall be specified taking into consideration the distribution of the load pressure in soil by the following formulae:

a) vertical pressure:

from railway moving train

from vehicles of highways and city roads (besides the load AK that is not calculated), as well as of industrial enterprises roads with circulation of trucks АБ

b) horizontal pressure

Where ν - intensity of vertical live load of railway moving train specified by Table 1 of Obligatory Appendix 5* for loading length λ = d + h and influence line peak position α = 0.5 but not more than 19.6 K kN/m (2K tf/m);

d - diameter (width) of the link (section) as per outside contour , m;

h - distance from the rail foot or road surface top to the top of the link when vertical pressure is determined or to the horizon under consideration when horizontal (lateral) pressure is determined;

τn - factor determined by formula (6);

ψ - linear load, kN/m (tf/m), determined by Table 12;

)10(;0 ha

pv +=

ψ

)9(;7.2 h

pv +=

ν

)11(nh pp τν=

SNiP 2.05.03-84 Page 32

αo - distribution area length, determined by Table 12.

2.17. *Characteristic horizontal transverse load from centrifugal force for bridges located on the curves shall be taken from each track or traffic lane in a form of uniformly distributed load of intensity νh or with the concentrated single force Fh. Values νh and Fh shall be specified:

a) from moving train on common railway bridges designed:

for the load C14 -

but not more than 0.15 ν;

for the load C10 -

but not more than 0.15 ν,

where r - radius of curve, m;

ν - weight of load from the moving vehicles, kN/m (tf/m) of track, specified in accordance with item 2.11;

b) from moving train on bridges of industrial enterprise railways - by the formula where νl – the maximum speed installed for train traffic on curves of the given radius, km/h;

c) from trains of subway and the tram – by the formula where u - the value equal to: 0.241 kN (h/km2) [0.0246 tf (h/km2)] - for the subway trains and

0.143 kN (h/km2) [0.0146 tf (h/km2)] - for the tram trains; d) from highway load AK for all bridges with curve radius:

250 m and less by the following formula

above 250 to 600 m (when bridges are situated on curves of big radius the load from centrifugal force is ignored in calculation) - by the following formula

but in all cases the value νh should be not less than and more than 0.49K kN/m (0.050K tf/m)

where P - force equal to 4.4 kN (0.45 tf);

M – moment equal to 1079 kN⋅m (110 tf⋅m);

,180νν

rh =

,60νν

rh =

*)12(,008.02

νν

νr

lh =

)13(,2

ru l

hν

ν =

)14(,KPh λ

ν =

)15(,KrM

h λν =

)/3.1(/7.12 mtfKr

mkNKr

SNiP 2.05.03-84 Page 33

e) from load АБ for bridges on the industrial enterprise roads with the curve radius 400 m and less (when bridges are situated on curves of big radius the load from centrifugal force is ignored in

calculation) - by the following formula

where G - weight of one car (sum of loads onto the front and rear axles), determined by Table 10.

In multi-track (multilane) traffic the loads νh and Fh are considered with the factors s1 in accordance with item 2.14, at this, the loads νh from all traffic lanes (except the one), loaded with vehicle load AK, are taken with factors s1= 0.5.

Table 12

For loads

HK-80 НГ-60 АБ-51 АБ-74 АБ-151 Parammeter with filling height *, m

1 and 1.5 and 1.3 and less than

1.9 and less than

3 and less than

more more more 1.3 more 1.9 more 3

ψ 186(19)

108(11)

186(19)

42(4.3) 186(19)

66(6.7) 186(19)

93(9.5)

α0 3 3 3 -0.3 3 -0.15 3 0

* In cases when fill height h is less than 1 m with load HK-80 and less than 1.5 m with load НГ-60, the value of pressure on to the pipe part under consideration shall be determined taking into account the pressure distribution in the soil at an angle to the vertical arc tg ½. The height of the load νh and Fh application (from the rail head or top of road surface) should be specified , in m: 2.2 - for railway moving train; 2.0 - for subway cars and the tram; 1.5 - for highway vehicles of load AK; 2.2; 2.5 and 3.1 - for loads АБ-51, АБ-74 and АБ-151. Note. Centrifugal forces of loads НК-80 and НГ-60 shall be ignored in calculation of the bridges.

2.18. *The characteristic horizontal transverse load from the moving vehicle impacts not regarding a number of tracks or traffic lanes on the bridge shall be specified: a)* from the railway moving train - in the form of uniformly distributed load applied in the level of rail head top and equal to: for trains of railways - 0.59K kN/m (0.06K tf/m); for trains of subway - 1.96 kN/m (0.2 tf/m); for the tram - 1.47 kgN/m (0.15 tf/m), where class K is class of load CK. The barrier-type protection steel members fabricated in conformity with GOST 26804-86 (group 11 MO and 11 МД) are not designed for the action of horizontal loads Bolt anchoriage assembly fixing of barrier protection uprights shall be checked separately for the action of: horizontal force responded to the shear of four bolts of fixing; moment originating from the force corresponding to rupture of two close-located bolts relative to the opposite rib;

)16(20rGFh =

SNiP 2.05.03-84 Page 34

b) from vehicle load AK - in the form of uniformly distributed load equal to 0.39K kN/m (0.04K tf/m), or concentrated force equal to 5.9K kN (0.6K tf), applied in the level of roadway surface top, where K is class of load AK; c) from load АБ - in the form of concentrated force applied to deck structure in the level of roadway top or to the roadway crash-barriers and equal to 0.2 G, where G is a weight of one vehicle (sum of loads onto the front and rear axles), determined by Table 10. When designed the roadway crash barriers members as well as their fastenings the horizontal load shall be specified as follows: a) for highway and city bridges: for solid rigid reinforced concrete parapet-type protection – in the form of transverse load 11.8K kN (1.2K tf) distributed by length 1 m and applied to the parapet in the level of 2/3 of parapet height (from surface of roadway); for curbs - in the form of transverse load 5.9K kN (0.6K tf), distributed by length 0.5 m and applied in the level of the curb top; for cantilevered uprights of semi-rigid steel barrier protections (with a distance from 2.5 to 3.0 m between uprights) - in the form of concentrated forces acting simultaneously in the level of guiding planks and equal to: across the roadway – 4.41K kN (0.45K tf); along the roadway - 2.45K kN (0.25K tf); where K is class of load AK. For steel barrier protections with continuous guiding planks the load acting along the bridge can be distributed to four uprights in series. The transverse loads HK-80 and НГ-60 from the vehicle impacts are not considered. b) in bridges on industrial enterprises roads (for loads АБ) – in the form of equal pressure (from concentrated force 0.2G indicated in sub-item “c” ) applied to the upper part of protection (parapet or curb) at areas having dimensions by height and length for the loads, respectively: АБ-51 ………… 20x45 АБ-74 ………… 25x50 АБ-151 ………… 30x60 Notes. Characteristic horizontal transverse load from impacts of moving train for bridges on railways of industrial enterprises in cases when the maximum traffic speed is limited to 40 km/h can be taken equal to 0.3K kN/m (0.03K tf/m), but with traffic speed 80 km/h and more - in values provided for the railways of general network (see sub-item “a”).

2.19. *.The characteristic horizontal longitudinal load from braking or traction forces of moving vehicles should be taken equal to:

a) when designed the members of span structures and piers of the bridges, % to characteristic vertical moving live load: from railway load CK, subway trains and the tram - 10 ; from equally distributed part of load AK (loads ignore the weight of bogies) – 50, but not less than 7.8K kN (0.8K tf) and not more than 24.5K kN (2.5K tf); from loads АБ-51 and АБ-74 (to weight of one car) - from 45 (with λ ≤ 20 m) to 60 (with λ ≥ 60 m ); from the load АБ-151 (to weight of one car)- from 30 (with λ ≤ 25 m) to 40 % (with λ ≥ 60 m); for intermediate λ the load value is determined by interpolation;

b) when designed the expansion joints of bridges on highways of category I-III, I-в, II-к, II-в, III-в, III-к, IV-в, IV-к and city bridges - 6.86K kN (0.7K tf). on highways of categories IV and V as well as of intra-economy roads - 4.9K kN (0.5K tf); industrial enterprises for load АБ – 50 % to the weight of equivalent car. In computations in the case “a” the height of applying the horizontal longitudinal loads shall be taken in accordance with item 2.18*.

SNiP 2.05.03-84 Page 35

Horizontal transverse load when computed the expansion joints shall be applied in the level of roadway and taken in the form of two equal forces distanced from each other to 1.9 m for load AK and to rear wheels track width for load АБ as per Table 10. The longitudinal load shall be taken : from one track in case of two railway tracks and from two tracks in case of three railway tracks and more; from all lanes of one direction at any number of traffic lanes on the bridge and from all traffic lanes if the traffic will be changed for one-sided traffic in the future. In all cases the factor s1 should be taken into consideration according to item 2.14. The longitudinal load of the vehicles standing on the sliding triangle near the abutments is not considered. In bridges with beam spans the longitudinal load can be applied in the level of : the roadway part – when designed the abutments; centre of bearing parts - when designed the intermediate supports, at this, the moment influence of load transfer is permitted to ignore. Longitudinal force of braking or traction force to be applied to the fixed bearing parts shall be specified as 100% of full longitudinal force acting to the deck. At this, the longitudinal force from moving bearing parts of neighbouring span mounted on the same pier shall not be taken into consideration, except the case of location in simple spans of fixed bearing parts from the side of the shorter span adjacent to the pier. The force to the pier in the given case should be taken equal to the sum of longitudinal forces transmitted through bearing parts of both spans but not more than the force transmitted from the side of the longer span in its fixed bearing position. The force transmitted to the pier from the fixed bearing parts of continuous and temperature-continuous decks, when it is proved by calculation, can be taken equal to full longitudinal load of the deck with subtraction of friction forces in moving bearing parts with minimum friction coefficients, but not less than the value loaded to the pier in distribution of full longitudinal force among all intermediate piers in proportion to their rigidness. For railway bridges in determination of longitudinal horizontal load from braking or traction forces in case of application of timber supports as well as flexible (from separate poles) steel and reinforced concrete supports the intensity of moving vertical live load ν can be specified equal to 9.81K kN/m (K tf/m). Notes.When designing in the railway bridges the devices intended to take up longitudinal loads it is necessary to consider the total traction force in the form of distributed load equal in respect to the load weight, % : - with loading length 40 m and more 10 - ditto, 100 m and more by interpolation - with intermediate values

2.20. *The characteristic live load for pedestrian bridges and sidewalks shall be taken in the form of: 1) vertical equally distributed load: a) to the pedestrian bridges – 3.92 kPa (400 kgf/m2); b) to sidewalks on the bridge (when considering in complete with other loads) - by the following

formula

but not less than 1.96 kPa (200 kgf/m2),

where λ - length of loading (sum of lengths when loaded two sections and more), m;

2) equally distributed load, considered in absence of other loads:

)17(/,2400(0196.092.3

2mkgfpkPap

λ

λ

−=

−=

SNiP 2.05.03-84 Page 36

a) vertical - when designed only the sidewalk members of railway bridges and bridges of subway with ballast way – 9.81 kPa (1000 kgf/m2); when designed sidewalk members of other bridges - 3.92 kPa (400 kgf/m2);

b) vertical and horizontal - when designed the city bridge parapets - 0.98 kN/m (100 kgf/m);

3) concentrated pressures considered in absence of other loads: a) vertical - when designed sidewalk members of city bridges – 9.8 kN (1 tf) with distribution

area from the car wheel 0.015 m2 (0.15x 0.10 m), of other bridges - 3.4 kN (350 kgf);

b) vertical or horizontal when designed the bridge parapets - 1.27 kN (130 kgf);

When designed the sidewalk members of bridges on intra-economy roads as well as on the service ways of bridges on highways of any category the equally distributed load is taken equal to 1.96 kPa (200 kgf/m2). When designed the main structures of bridges the said load to the sidewalks is ignored. Note. When designed the sidewalk members the loads of devices intended for inspection of bridge structure should be considered as well.

2.21. * Dynamic coefficients 1+µ for loads from the moving vehicles of railway, highways and city roads should be taken as equal : 1) to vertical loads CK, ε CK and AK (including pressure of single axis) as well as for loads from the subway train and the tram: a) for members of steel and steel reinforced concrete decks as well as for members of steel supports: of railway bridges and separate bridges for tracks of subway and the trams of all systems (except the main members of main girders of continuous deck) not depending on the roadway type (on the ballast or cross-members)

but not less than 1.15; of main members of main girders of the railway bridges with continuous deck and of combined bridges of all systems for the highway and railway loads (including subway trains) but not less than 1.15 for railway bridges and 1.10 for combined bridges;

of members of highway and city bridges of all systems, except the main girders (beams) and towers of suspension and cable-stayed bridges,

of members of main girders and towers of the suspension and cable-stayed bridges b) for reinforced concrete beam spans of frame structures (including open-web above-arch structures)

as well as for reinforced concrete open-web thin-walled and leg-type supports: of railway and other bridges under the rail tracks

but not less than 1.15; of combined bridges - by the formula (22), but not less than 1.10; of highway and city bridges

)18(,30

1811λ

µ+

+=+

)19(,30

1411λ

µ+

+=+

)20(,5.371511

λµ

++=+

)21(,70

5011λ

µ+

+=+

)22(,20

1011λ

µ+

+=+

)23(,135

4511 λµ

−+=+

SNiP 2.05.03-84 Page 37

but not less than 1.0; c) for reinforced concrete links of pipes and pedestrian underpasses:

on the railways and subway tracks with total thickness of ballast including filling (beginning from the rail foot): m and less – by the formula (22); 1.00 m and more - 1+µ = 1.00; for intermediate values of thickness - by interpolation; on highways - 1+µ = 1.00;

d) for reinforced concrete and concrete arches with solid above-vault structure, for concrete piers and links of pipes, ground bases and all foundations 1+µ = 1.00;

e) for arches and vaults of the arched reinforced concrete spans with open-web above-arch structure: of railway bridges

where ƒ - rise of arch; l - span of arch; of highway and city bridges but not less than 1.00;

f) for members of expansion joints positioned in the level of roadway of highway and city bridges and their anchorage (to probable vertical and horizontal forces). 1+ µ = 2.00 h) for wooden structures : railway bridges: for members 1+ µ = 1.10; for integration 1+ µ = 1.20; for highway and city bridges 1+ µ = 1.00;

2) to vertical live load AБ: a) for members of steel and steel reinforced concrete decks as well as of members of steel

supports

but not less than 1.00; b) for reinforced concrete beam span structures, reinforced concrete open-web thin-wall and leg-type supports as well as links of pipes without filling beneath the pavement structure

but not less than 1.00; c) for concrete piers and links of pipes, ground bases and all foundations, and with total thickness of filling (including the pavement thickness) not less than 1.0 m - for reinforced concrete links of pipes, and not less than 0.5 m - for other members, listed above in sub-item “b”, 1+µ = 1.00 with thickness of filling (including the pavement thickness) less than indicated in sub-item “c” the dynamic coefficients values, listed in sub-item “b” are taken by interpolation between values, taken according to sub-items “b” and “c”;

)24(,)4.01(100

1211f

l+

++=+

λµ

)25(,250

7011 λµ

−+=+

)26(,115

8111 λµ

−+=+

)27(,135

8111 λµ

−+=+

SNiP 2.05.03-84 Page 38

d) for wooden structures for members 1+µ = 1.10 for integration 1+µ = 1.20 For the train of vehicles the loads АБ – when calculated for the case “b” , item 2.13 1+µ = 1.00

3) to the single vehicles for span structures, open-web, thin-wall and leg-type supports of highway and city bridges. to load HK-80 1+µ = 1.30 at λ ≤ 1.0 m; 1+µ = 1.10 at λ ≥ 5.0 m; for intermediate values λ - by interpolation; to load НГ-60 1+µ = 1.10;

4) to vertical live loads for pedestrian bridges and to the loads on the sidewalks 1+µ = 1.00;

5) to horizontal live loads and soil pressure to the piers from the vehicles of the railways and highways

1+µ = 1.00; 6) when calculated the bridge for endurance (see Table 6) the dynamic addition µ obtained from

formulae (18)-(27) (including limitations) has to be multiplied by 2/3. The value λ (of the span or length of loading) in the formulae shall be taken as: a) for main members of the main girders (simple beams, arches, frames) as well as for longitudinal and transverse girders when loaded the part of influence line that defines their participation in behavior of main girders - equal to the span length or to the length of loading the line of influence, if this length exceeds the span value; b) for main members of the main girders of continuous systems - equal to the total of lengths of loading parts of influence lines (together with the parts dividing them); c) when calculated for local load (at loading that part of the line of influence which considers the force of the local load): the longitudinal beams and longitudinal ribs of orthotropic decks - equal to the length of their span; the transverse beams and transverse ribs of orthotropic decks - equal to total length of longitudinal beams in adjacent panels; the hangers, uprights and other members, working only for local load - equal to length of loading of the line of influence; of the ballast pocket (across the track) - equal conventionally to zero; of reinforced concrete slabs of railroad laid on the steel beams, when calculated the slab across the track - equal to the width of slab, when calculated the slab along the track - equal to length of panel of the longitudinal beam; of reinforced concrete slabs of the roadway, laid on the steel beams, when calculated the slabs across the bridge - equal to a distance between the beams supporting the slab;

d) when loaded the lines of influence, taking into consideration the main and the local loads simultaneously - separately for each of these loads;

e) for the members of any supports - equal to length of loading the line of influence of bearing reaction determined as the total of lengths of parts under loads (together with the parts dividing them);

f) for links of pipes and pedestrian underpasses - equal to width of link. . Notes. In case the railways of industrial enterprises apply the limited maximum speed on the bridge ( νt < 80 km/h ), the designed value of dynamic coefficient can be decreased by means of multiplying the corresponding dynamic addition to the ratio νt / 80, at this the dynamic coefficient shall be taken not less than 1.10.

SNiP 2.05.03-84 Page 39

2.22. *. The load safety factors γf to live loads and forces given in items 2.11-.21* shall be taken equal to:

a) for railway loads CK and ε CK - as per Table 13; Table 13

Load safety factor γf when designing

F o r c e s

structures of bridges depending on loading length λ*, m

Links of

0 50 150 and more

pipes

Vertical 1.30 1.15 1.10 1.30 Horizontal 1.20 1.10 1.10 1.20

Soil pressure of moving train on the sliding triangle

1.20 – independently on loading length

-

__________________ Here λ is a length of loading the line of influence minus length of parts loaded by train with empty cars (with λf =1); for intermediate values λ shall be taken by interpolation.

b) for the load AK of highway vehicles - as per Table 14; c) to wheel (HK-80) and crawler (НГ-60) loads and their forces - 1.0; d) to loads from moving train of subway and the tram - by the formula

but not less than 1.10, where λ - loading length, m, taken as per Table 13;

Table 14 Load Application case Load safety

factor λf Bogie When computing the bridge roadway

members 1.50

When computing all other bridge members

1.50 at λ* = 0 1.20 at λ ≥ 30 m

When determined the weight in seismic designs

1.20

Uniformly distributed In all computations of bridges structures and links of pipes for vertical and horizontal forces

1.20

Single axis When checked the bridge roadway members designed for the load AB

1.20

*Here λ is a length of influence line of one sign; for intermediate values λ shall be taken by interpolation

e) to distributed loads for pedestrian bridges and sidewalks when computing: the members of pedestrian bridges and sidewalks (except sidewalks of intra-economy road bridges and of service ways) as well as the parapets of city bridges - 1.40; the span structure and piers when considered together with other loads - 1.20; the sidewalks on the bridges of inta-economy roads and service ways on the bridges of highways of any category - 1.10;

f) to distributed and concentrated loads for crash barriers of the roadway as well as to concentrated pressures to sidewalks and handrails - 1.10;

)28(,)10

1(3.1 3

λλ −=f

SNiP 2.05.03-84 Page 40

g) to truck load АБ and their forces - depending on the specific weight of rock material λνb, intended to be carried by this road: at λνb ≤ 17.7 kN/m3 (1.8 tf/m3) …………. 1.1 at λνb = 39.2 kN/m3 (4.0 tf/m3) …………. 1.4 at intermediate values ……….. by interpolation

OTHER LIVE LOADS AND FORCES 2.23. *. Characteristic value of wind load Wn shall be determined as a sum of characteristic values of mean Wm and pulsation Wp components: Wn = Wm + Wp Characteristic value of mean component of wind load Wm at a height z above surface of water or ground is determined by the formula Wm = Wo kCw where Wo - characteristic value of wind pressure taken as per SNiP 2.01.07-85 depending upon the wind region of the Russian Federation territory where the structure is under construction; k - factor that takes into consideration for the open area (type A) the change of wind pressure by height z, taken as per SNiP 2.01.07-85; Cw - aerodynamic coefficient of face resistance of bridge structures and of moving train of railroad and subway, determined in special Appendix 9*. Characteristic value of pulsation component of wind load Wp at a height z shall be determined as per instructions of SNiP 2.01.07-85: Wh = Wm ξ L ν where ξ - dynamic coefficient; L - pulsation coefficient of wind pressure on the level z; ν - pressure pulsation space correlation coefficient for designed surface of the structure. When determined the wind load pulsation component relative to the bridge structures the following guidance can be taken:

a) the product of coefficients Lν shall be taken equal to : 0.55-0.15 λ /100, but not less than 0.30, where λ - length of span or height of pier, m;

b) dynamic coefficient ξ for simple beam structures shall be determined with assumption that the considered structure in horizontal plane is the dynamic system with the single degree of freedom (with lower frequency of own oscillations ƒ1, Hz) and its value has to be determined by schedule given in item 6.7 SNiP 2.01.07-85 depending on the given parameter ∑ and logarithmic decrement of dumping σ = 0.3 - for reinforced concrete and steel reinforced concrete structures and σ = 0.15 - for steel structures. The dynamic coefficient is taken equal to 1.2 if: beam span structure is a continuous one; for simple beam structure there is a condition that ƒ > ƒ, where ƒ, Hz is a limit value of own oscillation freequencies, described in item 6.8 of SNiP 2.01.07-85, that allows in different wind areas to ignore the inercia forces, originating with natural oscillations . In calculation of highway and city bridge structures the wind force to the railless traffic and to the tram, standing on these bridges, is ignored. Standard span structures shall be designed, as a rule, for possibility to be used in wind region V ( with designed height to the span bottom: 20 m – for through bridge and 15 m for deck-type bridge) and shall provide the opportunity to reinforce them when applied in wind regions VI and VII. Characteristic intensity of full transverse horizontal wind load when designed the individual (not standard) span structures and piers shall be taken not less than 0.59 kPa (60 kgf/m2) when loaded the structures with vertical live load and 0.98 kPa (100 kgf/ m2) in absence of loading with this load.

SNiP 2.05.03-84 Page 41

Horizontal transverse wind load acting to separate bridge structures as well as to the train, being on the railway bridge (subway bridge) shall be taken equal to the product of wind load intensity by effective wind surface of the bridge and moving train. The effective wind surface of bridge structure and moving vehicle shall be taken equal to: - area of projection of all elements of the windward truss to the plane in perpendicular to wind direction for the main girders of open-web spans and open-web piers, at this, for steel girders with a triangular or skew lattice it can be taken within 20% of area confined by the girder contours; - side surface of deck framing not covered with the truss chord for the roadway part of the open-web spans; - side surface of the windward main girder or box and windward bridge beam for decks with solid web and for stringers of wooden bridges; - area of projection of the pier body from the level of soil or water to the plane in perpendicular to the wind direction for the solid piers; - area of solid strip 3 m high with a centre of pressure at a height 2 m from the rail head for the railway moving train ( including trains of the subway). Wind load distribution along the span length can be taken as uniform. Characteristic intensity of wind load taken into consideration during the construction and erection shall be determined on the base of wind load mean component value possible during the given period in the given region. Depending on the character of executed work, in availability of special grounds that provide the corresponding limit of time and duration of execution of separate stages of construction, the characteristic value of wind load mean component for checking the stress (but not the stability) can be decreased but it should be not less than 0.226 kPa (23 kgf/m2). To check the standard structures at the stage of construction and erection, the wind load characteristic intensity value shall be taken in accordance with the norms for wind region III. Characteristic horizontal longitudinal wind load for open web decks shall be taken in size of 60% , for decks with solid beams – in size of 20%, in respect to full characteristic transverse wind load. Characteristic horizontal longitudinal load to the piers of bridges above the level of soil or the lowest water level shall be taken equal to transverse wind load. Longitudinal wind load to the traffic being on the bridge is ignored. Wind load forces in the members of longitudinal and transverse braces between the trusses of spans shall be determined, as a rule, by means of three-dimensional calculations. In case of making two longitudinal brace systems in lattice span structures it is allowed to distribute the wind transverse pressure to each system, but wind pressure to the roadway and to the moving traffic can be transmitted completely to those braces which planes carry the traffic. Horizontal force from longitudinal wind load acting to the span structure shall be taken as transferred to piers in the level of the centre of bearing parts for bridges with beam decks, and in the level of the frame cross-bar axis for bridges of framed structure. Distribution of forces between piers shall be taken the same as of horizontal force from deceleration according to item 2.20*. Cable-stayed and suspension bridges are required to be tested for aerodynamic stability and oscillations resonance in direction perpendicular to wind flow. The aerodynamic stability test should determine a critical wind velocity that can cause the flutter occurrence (appearance of dangerous flexure-torsion oscillations of suspension girder) due to the reason of interaction between the air flow and the structure. The critical speed corresponding to the flutter occurrence, determined by the results of aerodynamic model tests or determined by computation should be more than the maximum wind velocity available in the bridge location area, but not less than 1.5 times.

2.24. Characteristic ice load from ice pressure to the bridge piers shall be taken in the form of forces determined as per Special Appendix 10*.

2.25. Characteristic load from vessel impact to bridge piers shall be taken in the form of concentrated longitudinal or transverse force and limited with values indicated in Table 15, depending on class of internal water ways.

Table 15

SNiP 2.05.03-84 Page 42

Load from vessel impact, kN (tf) Along bridge axis from the side

of span Across bridge axis from the

side Class of internal water ways

navigable unnavigable upstream downstream, no current; and upstream

I 1570(160) 780(80) 1960(200) 1570(160) II 1130(115) 640(65) 1420(145) 1130(115) III 1030(105) 540(55) 1275(130) 1030(105) IV 880(90) 490(50) 1130(115) 880(90) V 390(40) 245(25) 490(50) 390(40) VI 245(25) 147(15) 295(30) 245(25) VII 147(15) 98(10) 245(25) 147(15)

The load of the vessel impact shall be applied to the pier at a height 2 m from the designed navigable level except the cases when the pier has projections fixing the level of this load action and when with less high level the load causes the more significant action. For piers protected against the vessel impact as well as for wooden piers of highway bridges through the internal water ways of class VI and VII the vessel impact load can be ignored. For one-row reinforced concrete pile piers of highway bridges through the internal water ways of class VI and VII the load along the bridge axis can be considered in size of 50%.

2.26. *. Characteristic temperature climatic influence shall be taken into consideration when computed the displacement in bridges of all systems, when determined the forces in outside statically indeterminate systems as well as when computed the members of steel-and-concrete decks. The mean as per section characteristic temperature of the members or of their parts can be taken equal to: characteristic temperature of ambient air for concrete and reinforced concrete members in cold season of a year as well as for steel structures in any season of a year; characteristic temperature of ambient air with subtraction of the value numerically equal to 0.2 α, but not more than 10°C, where α is a thickness of the member or its part in cm, including the highway bridge roadway floor pavement, - for concrete and reinforced concrete members in warm season of a year. The temperature of complicated cross-section members shall be determined as the weighted average as per temperature of separate members (webs, flanges, etc.). The ambient air characteristic temperature in warm tn,T and cold tn,X seasons of a year shall be specified as follows:

a) when worked out the standard designs as well as the secondary-use designs at the territory of the country: for structures constructed in the regions with the designed minimum air temperature minus 40°C,

tn,T = 40 C; tn,X = - 50°C; for structures constructed in other regions tn,T = 40 C; tn,X = - 40°C; b) in other cases tn,T = tVII + T (29) where tVII - mean air temperature of the most hot month taken as per SNiP 2.01.01- 82; T - constant value for determination of air temperature of the most hot days taken as per isolines map in SNiP 2.01.01-82, °C. Characteristic temperature tn,X is specified equal to the designed minimum air temperature in the region of construction in conformity with item 1.39.

SNiP 2.05.03-84 Page 43

Solar radiation influence to the temperature of the members shall be considered in the form of additional heat for 10 °C of the sun-lighted surface layer of 15 cm thick (including the pavement of the roadway floor). The structure locking temperatures, unless otherwise specified in the design, shall be taken equal to: t3,T = tn,T - 15° C; t3,X = tn,X + 15°C; The temperature of the structure at the moment of locking t3 can be determined by the formula t3 = 0.4 t1 + 0.6 t2 (30) where t1 - mean air temperature of a period previous to the locking, equal to To; t2 - mean air temperature at a period previous to the locking, equal to 0.25 To ; To- the period, h, numerically equal to the structure members reduced thickness, cm, that shall be determined by dividing the doubled area of cross section of the member (including the pavement) to its perimeter on the border with ambient air. When computed the steel-and-concrete decks it shall be taken into consideration the influence of temperature nonuniform distribution as per section of members, caused by changing the temperature of air and solar radiation. In calculation of displacements the coefficient of linear expansion shall be taken equal to 1.2⋅10 -5 for steel and steel-and-concrete structures and 1.0⋅10-5 for reinforced concrete structures. 2.27. *. Characteristic resistance of friction in moving bearing parts shall be taken in the form of horizontal longitudinal reactive force Sf and determined by the following formula

Sf = µn Fv (31) where µn - characteristic value of friction coefficient of bearing parts during their displacement, specified equal to mean value out of probable extreme values:

Fv - vertical component when loads under consideration are in force with the load safety factor γf = 1. The maximum and minimum friction coefficient values shall be specified, respectively, equal to: a) 0.40 and 0.010 with rolled, sector or shafted bearing parts; b 0.020 and 0 (conventionally) with rocker uprights or hangers; c) 0.40 and 0.10 with tangential and flat steel bearing parts; d) as per Table 16 with moving bearing parts with gaskets from fluoroplastic in complete with polished stainless steel plates.

Table 16 Friction coefficient at a temperature of the most cold five days as per SNiP 2.01.01-82 with probability 0.92

minus 10°C and more minus 50°C

Mean pressure in bearing parts as per fluoroplastic, MPa (kgf/cm2) µ max µ mix µ max µ mix

9.81 (100) 0.085 0.030 0.120 0.045 19.6 (200) 0.050 0.015 0.075 0.030 29.4 (300) 0.035 0.010 0.060 0.020

Note. Friction coefficients with intermediate values of negative temperatures and mean pressures are determined by interpolation. The design forces from friction in moving bearing parts of beam span structures depending on the type and character of computation shall be specified as follows: Sf, max = mmax Fv , if with combination of loads under consideration the friction forces increase total effect to the computed member of the structure;

)32(2

minmax µµµ

+=n

SNiP 2.05.03-84 Page 44

Sf, max = mmix Fv , if with combination of loads under consideration the friction forces decrease total effect to the computed member of the structure. Load safety factors γf to forces Smax and Smin are not introduced. Determination of effect to deck constructions from friction forces originating in moving bearing parts of rolled, sector, and shafted types with a number of bearing parts in cross direction more than 2 shall be carried out with the behavior condition coefficient equal to 1.1. Piers (together with foundations) and bridge decks shall be checked for effect of designed friction forces originating from temperature deformations with dead loads in force. Bearing parts and their fastening members, as well as parts of piers and parts of decks adjacent to bearing parts shall be checked for designed friction forces originating from dead and live (less dynamics ) loads. With arrangement on the pier of two rows of deck moving bearing parts, as well as with erection in continuous and temperature-continuous decks of fixed bearing parts on intermediate pier the longitudinal force shall be specified not more than a difference of friction forces with the maximum and minimum coefficients of friction in bearing parts. The maximum and minimum coefficients of friction in moving bearing parts for group of piers taking up in simple and temperature-simple decks the longitudinal forces of one sign (µ max,z and µ min,z , respectively) can be determined by the following formula

where µ max , µ min - maximum and minimum values of friction coefficients for type of bearing parts to be erected; z - number of piers in group. The right part of the formula (33) is calculated with sign “plus” when determined µ max,z , and with sign “minus” when determined µ min,z.. Reactive longitudinal force value Sh, kN (kgf) originating in rubber bearing parts due to their resistance to shear is calculated by the following formula

Where δ - displacements in bearing parts, cm; α - total thickness of rubber layers, cm; A - area of rubber bearing part or several bearing parts in case of their close location under one end of the beam, m2 (cm2); G - shear modulus which values, when determined the designed longitudinal forces, depend on the characteristic ambient air temperature and are taken for applied brands of rubber as per the following Table. Brand of rubber

Rubber shear modulus, MPa (kgf/cm2), at characteristic ambient air temperature , °C

20 -20 -30 -40 -50 -55 HO-69-1 0.88

(9.0) 0.96 (9.8)

1.12 (11.4)

1.43 - -

ИРП-1347 0.55 (5.6)

0.58 (5.9)

0.59 (6.0)

0.63 (6.4)

0.75 (7.6)

0.86 (9.0)

Note. Intermediate values are taken by interpolation. Formula (35) is excluded. Bearing units of deck beams or slabs should include as a rule, only one rubber bearing part along the bridge axis, but across the bridge several similar bearing parts made of one brand rubber can be

)33(,)(1)(5.0, minmaxminmaxmin,max,

−±=+= µµµµµzzz

)34(AGSh αδ

=

SNiP 2.05.03-84 Page 45

installed. Two near-located rubber bearing parts can be installed alongside the bridge axis if the project proves it by the corresponding computation.

2.28. *.Effect of frost heave within the season frosting (defrosting) layer when constructed in permafrost soil, as well as in heave soil seasonally frozen more than 2 m deep, shall be specified in the form of vertical tangential forces applied along the perimeter of foundation (or piles). Frost heave forces shall be taken in accordance with the requirements of SNiP 2.02.04-88.

2.29. Construction loads (dead weight, weight of scaffolds, cranes, workers, tools, small equipment, one-sided outward thrust, etc.) applied to the structure during erection or construction, as well as during fabrication and transportation of members shall be specified as per design data with provision of conditions of work procedure and requirements of SNiP III-4-80*. To determine the crane load the weight of lifted loads and weight of moving boom shall be taken with dynamic coefficients equal, respectively, to 1.20 (0.85) with weight up to 196kN (20 tf) and 1.10 (0.95) if the weight is more. At this, if the unloaded crane can influence unfavourably on behavior of the structure under computation, the crane is considered in designs without the load. When designed the reinforced concrete structure members for action of forces originating in their transportation the member dead weight load shall be introduced into computation with the dynamic coefficients equal to: 1.6 - when transported by highway; 1.3 - when transported by railway The dynamic coefficients taking into account the transportation conditions can be specified of smaller value if it is proved by experience, but not less than 1.3 for highway transportation and not less than 1.15 for railway transportation.

2.30. Earthquake loads can be specified according to requirements of SNiP II-7-81*.

2.31. *. Load safety factors γf to other live loads and forces given in items 2.24* -3.30 shall be specified by Table 17*. In checking the piers body strength in case of using them for balanced cantilever erection of decks, as well as in checking the fastening strength of anchors that fasten the deck to the piers, it is necessary to introduce the load safety factors to the dead weight of assembled cantilever parts producing the bending moments of different sign onto the pier, taking into consideration the special conditions of fabrication and erection of assembled parts (blocks). With ready-made technology of fabrication for reinforced concrete blocks the load safety factors of dead weight, when checked the strength of the pier body and of the fastening anchors, can be determined by the following formula: for one cantilever

for another cantilever

where z - number of blocks to be erected each side. Table 17*

Other live loads and forces Load safety factor, γf Wind force at: performance of bridge construction and erection

1.4 1.0

Ice load 1.2 Load of vessel impact 1.2 Temperature climatic deformations and effects 1.2

)37(962.01.01 ≤−z

)36(038.11.01 ≥+z

SNiP 2.05.03-84 Page 46

Effect of frost heave of soil 1.3 Resistance force of friction in moving bearing parts As per item 2.28* Construction loads Dead weight of auxiliary devices 1.1 (0.9) weight of stored building materials and effect of artificial regulation in auxiliary constructions

1.3 (0.8)

weight of workers, tools, small equipment 1.3 (0.7) weight of cranes, pile drivers and trucks 1.1 (1.0) forces from hydraulic jacks and motor-driven winches during lifting and transfer

1.3 (1.0)

Forces of friction during transportation of decks and other weights: - on skids and with fluoroplastic - on rollers - on cars

1.3 (1.0) 1.1 (1.0) 1.2 (1.0)

3) CONCRETE AND REINFORCED CONCRETE STRUCTURES BASIC DESIGN REQUIREMENTS

3.1. Concrete and reinforced concrete bridges and culverts shall be designed in conformity with the Standard CMEA 1406-78 (Council for Mutual Economic Assistance) to ensure the required structure reliability during occurrence of the limitting states of two groups provided with GOST 27751-88 (ST CMEA 384-87). For this purpose together with assignment of corresponding materials and fulfilment of envisaged constructional requirements it is necessary to make designs indicated in the present norms. The structure as a whole and its separate members shall be designed at the most unfavourable combinations of loads and forces that can occur at different stages of operation. Considered structural models, which general requirements are indicated in item 1.37, should correspond to adopted structural-manufacturing decisions, take into consideration the conditions of manufacture, transportation and erection of structures, characteristic features of their loading with dead and live loads, the sequence of prestressing and regulation of forces in the structure.

3.2. To avoid the limitting states of the first group the structural members of the bridges and culverts shall be computed as per strength, stability (form and position) and durability in accordance with the instructions of the present Section, at this, the durability design shall consider the loads and forces that can occur at the stage of normal operation. To avoid the limitting states of the second group the designs shall be carried out following the Table 18 .

Table 18 Design Principal reinforcement Stages of performance Formation of longitudinal cracks

Untensioned Normal operation

Stressed All stages (normal operation, erection of structure, prestressing, storage, transportation)

Formation of cracks, normal and inclined to longitudinal axis of member

Stressed All stages

Opening of cracks, normal and inclined to longitudinal axis of member

Untensioned and stressed (except members with stressed reinforcement, designed accord. to

All stages

SNiP 2.05.03-84 Page 47

category of requirements as per crack resistance 2a, see Table 39*)

Closing (compression) of cracks, normal to longitudinal axis of member

Stressed Normal operation

Limit of tangential stresses Untensioned and stressed All stages Strains (deflections)of decks in bridges of all purposes, and angles of profile change of roadway in highway and city bridges

Ditto Normal operation

3.3. Crack resistance designs in complete with structural and other requirements (for drainage and waterproofing of structures, frost resistance and watertightness of concrete) must ensure corrosion resistance of reinforced concrete bridges and culverts as well as prevent occurrence of damages in them at combined effect of force factors and unfavourable influence of environment. Members of reinforced concrete structures depending on the purpose, behaviour conditions and applied reinforcement shall satisfy to corresponding categories of requirements for crack resistance that provide different probability of crack formation (appearance) and ultimate designed values of their opening width (see item 3.95*).

3.4. Statically indeterminate structure members sections forces from loads and forces when designed the limitting states of the first and the second groups shall be determined, as a rule, taking into account the inelastic deformations of concrete and reinforcement, and cracks availability. In structures for which the design methods including the inelastic properties of concrete are not developed, as well as for intermediate design steps with accounting the inelastic properties of concrete the forces in member sections can be determined by assumption of their linear elasticity.

3.5. If in the process of fabrication or erection of the structure the structural models or geometric characteristics of sections are changed, then the forces, stresses and strains in the structure shall be determined by summation of them for all previous stages of work. At this, as a rule, the change of forces has to be considered in time due to shrinkage and creep of concrete and relaxation of stress in stressed reinforcement.

3.6. *.In structures with untensioned reinforcement the stresses in concrete and reinforcement shall be determined by rules of design of elastic materials not taking into consideration the behavior of concrete in the tensile zone (see items 3.48*, 3.94* and 3.100*).

3.7. *. In prestressed structures the stresses in concrete and reinforcement in sections normal to the longitudinal axis of the member shall be determined by rules of design of elastic materials considering the section as solid one. If in-situ casting concrete of stressed reinforcement placed in open canals has no bonding with concrete of the main structure (see item 3.170), it should be considered that the stressed reinforcement itself placed in open canals has no bonding with concrete of the structure. In determining the crack opening width in elements of prestressed structures (including with mixed reinforcement ) stresses in reinforcement shall be determined not taking into consideration the action of tensile zone of concrete. It is permitted to pass the tensile zone forces to reinforcement. The characteristics of the given section in all cases shall be determined taking into consideration stressed and untensioned reinforcement available in the section, following the item 3.48*. If the structure members are made of concrete of different classes, then the total working area of section shall be determined taking into account relevant modules of elasticity. In prestressed structures at the stage of concrete compression in working zone of concrete the area of closed and open canals are not taken into consideration. In designing these structures at the stage of operation the designed area of section of concrete can include the section area of injected

SNiP 2.05.03-84 Page 48

closed canals. In-situ casting concrete of open canals can be taken into consideration on condition of fulfilment of requirements as per item 3.104* of special process measures according to the item 3.170 and installation of untensioned reinforcement in in-situ casting concrete. At this, the crack opening width in in-situ casting concrete should not exceed dimensions accepted for members designed as per 3в frost resistance requirements category.

3.8. * Length (height)-composite constructions shall be checked for strength and frost resistance in sections coinciding with butt joints or crossing the butt zone. Butt joints should provide the transmission of designed forces without appearance of damages in in-situ casting concrete and on the ends of butted elements (blocks). Paste in butt joints is intended to seal butt joints and to transfer uniformly the compressive forces.

3.9. *. Railway bridge deck T-beam webs shall be designed with assumption of possible transverse displacement not less than 10 cm of track on the bridge. Cracks formation design of the bridge deck beam webs is recommended to perform taking into account torsion and bend of the webs (out of their plane).

3.10. *. The reinforcement preliminary stress is characterized by values of the initial (controlled) force, taking into consideration item 3.86, applied to the ends of stressed reinforcement via tension devices, and stable force equal to controlled one less the losses happened to the time under consideration. At this, reinforcement stresses corresponding to the controlled force should not exceed the designed resistance indicated in Table 31*, taking into consideration the behavior conditions coefficient according to item 3.43*. For prestressed reinforced members the design documents should indicate the values of controlled forces and relevant extensions (elongation) or reinforcement taking into consideration item 4 of Table 1 of Obligatory Appendix 11*.

The reinforcement extension value ∆p in general case is determined as follows:

where σp - stresses corresponding to the controlled force and specified taking into consideration the requirements of item 3.14; Ep - stressed reinforcement elasticity modulus; l - designed length of reinforcing member (distance from tendon anchor to point of reinforcement element with zero displacements) Other symbols are given in Table 1 and 2* of Obligatory Appendix 11*. In determining the designed action created by the stressed reinforcement force the load safety factors γƒ shall be specified equal to:

a) in availability of bonded reinforcement: 1 - for continuous lengthwise members;

as per item 3.86* - for composite members; b) 1 ± 0.1 - without bonded reinforcement (see item 3.65*).

3.11. When prestressed members are calculated the transfer to concrete of concentrated forces from the stressed reinforcement shall be placed in structures: with outer (end) and inner (framed-rod) anchors - in the point of bearing or fastening of anchors; with reinforcement having no anchors ( with anchoring by means of bonding the reinforcement with concrete) - at a distance equal to 2/3 of development length. The development length of forces during the force transfer from the stressed deformed bars to the concrete shall be as follows: smooth -20 d (d - bar diameter)

∫ Θ+=∆l

wxp

зз e

dxE 0

)38(,δ

σ

SNiP 2.05.03-84 Page 49

instantaneous by means of the cutting of bars (allowable at bar diameter not more than 18 mm) - 25 d. For structure members intended to operate in regions with mean ambient air temperature of the most cold five-day -40°C the development length has to be increased by 5d. The development length of forces from stressed strands of class K-7 in absence of anchors shall be specified in values as indicated in Table 19; for structure members intended to operate in regions with mean ambient air temperature of the most cold five day lower than -40°C, in case of strands of class K-7 the development length values should exceed the values indicated in Table 19 as follows: by 27 cm - at strand diameter 9 mm; by 30 cm - ditto 12 mm; by 38 cm - ditto 15 mm .

Table 19 For development length of forces lгр , see transfer strength of concrete corresponding to concrete of classes as per compression strength

Diameter of strands, class K-7, mm

B22.5 B25 B27.5 B30 B35 B40 B45 B50 and more 9 88 85 83 80 75 70 65 60 12 98 95 93 90 87 85 75 70 15 115 110 105 100 95 90 85 80 Notes. With instantaneous transfer of stressing force to the concrete (by means of strand cutting off) the beginning of development length should be specified at a distance equal to 0.25 lгр from the end face of the member.

3.12. * Reinforcement of development length of concentrated forces including from stressed reinforcing members shall be installed taking into consideration the tension-deformed state of this length determined with methods of elasticity theory or other proved methods of computation of local stresses.

3.13. The influence of shrinkage and creep of the concrete shall be taken into consideration when determining : losses of preliminary tensions in reinforcement; de-compressing of concrete in prestressed structures; changes of forces in structures with artificial control of stresses; displacement (strain) of structures due to continuous loads and actions; forces in statically indeterminate structures; forces in precast cast-in-place structures. Displacements (strains) of structures caused by live loads can be determined without taking into consideration the creep and shrinkage of the concrete. In computation of two-axis or three-axis compressed members the losses of stress in stressed structure and de-compressing of concrete due to its creep and shrinkage can be determined separately on each direction of force action. Stresses in prestressed structure members shall be determined by the controlled force with the deduction of: the first losses at the stage of compressing the concrete; the first and second losses at the operation stage. The first losses should include:

a) in posttensioning structures - losses due to the anchor deformation, reinforcement friction against surrounding devices, stress relaxation in reinforcement, (in size 50% of full volume), drop of temperature, quickly moved creep and due to deformation of forms (when reinforcement is tensioned onto the forms);

b) in post-tensioning structures - losses due to the anchor deformation, reinforcement friction against closed and open channels, stress relaxation in reinforcement (in size 50% of full volume).

The second losses should include:

SNiP 2.05.03-84 Page 50

a) in pretensioning structures - losses due to shrinkage and creep of concrete, stress relaxation in reinforcement (in size 50% of full volume);

b) - lin post-tensioning structures - due to shrinkage and creep of concrete, stress relaxation in reinforcement (in size 50% of full volume), bearing strain beneath spiral or hooped reinforcement coiled onto a concrete, deformation of butts between sections in length-composite structures. Individual values of listed above losses have to be determined as per Obligatory Appendix 11* taking into consideration item 3.15.

It can be allowed that second losses due to stress relaxation in reinforcement (in size 50% of full volume) occur uniformly and are finished completely during one month after stressing the concrete.

In designing the summary of first and second losses should be taken not less than 98 MPa (1000 kgf/cm2).

3.14. The reinforcement prestressing losses due to shrinkage and creep of concrete shall be determined taking into consideration the following directions:

a) time change of losses, ∆σp (t) due to shrinkage and creep of concrete can be determined by the formula ∆σp (t) = 1-e-0.1√t’) ∆σp (t → ∞), (39) where ∆σp (t → ∞) - finite (limited) values of losses in reinforcement due to shrinkage and creep of concrete defined by Obligatory Appendices 11* and 13* ; t - the time since the day of concrete compression when determining the losses due to creep, and the time since the day of ending the concreting, daily, when determining the losses due to shrinkage. e = 2.718 - the base of natural logarithms;

b) for structures intended to operate in ambient air humidity less than 40% the losses due to shrinkage and creep shall be increased by 25 % except for structures intended to operate in climatic subregion IVA according to SNiP 2.01.01-82 and not protected against solar radiation for which the mentioned losses are increased by 50%.

c) more precise methods for determination of losses and re-distribution of forces from shrinkage and creep of concrete, influence of reinforcement, age and transfer strength of concrete, stage-by-stage load application and durability of its action on each stage, deformation development speed in the time, reduced dimensions of cross sections, ambient air relative humidity and other factors can be used. These methods must be conformed in the established order. At this, normative strains of creep cn and shrinkage of concrete εn for classes of concrete corresponding to its transfer strength shall be specified as per Table 3 of Obligatory Appendix 11*.

3.15.

3.16. The designed length lo of compression members of reinforced concrete lattice trusses shall be specified by instructions relevant to determination of the designed length of compression members of steel lattice trusses (refer to Section 4). The designed length of legs of detached frames when legs are rigidly connected to the cross bar can be specified by Table 20 depending on the ratio of rigidness of the cross bar B1+Ebl1 and legs B2=Ebl2.

Table 20 Designed length of leg l at ratio of rigidness B1/B2 Ratio of cross bar l

to height of leg H 0.5 1 5 0..2 1.1 H H H 1 1.3 H 1.15 H H 3 1.5 H 1.4 H 1.1 H

Notes. With intermediate values of ratio L/H and B1/B2 the designed length lo can be determined by interpolation.

SNiP 2.05.03-84 Page 51

The designed length of piles (tubular piles, pole piles) including in members of trestle-type supports shall be specified taking into consideration deformability of soil and capacity of resistance against displacements of foundation and top of the support. On computation of the support parts or members as per longitudinal bend by means of constructional mechanics concerning determination of the designed (free) length of compression members, it is permitted to take into consideration the elastic fixing (elastic yielding) of the ends of members under consideration due to soil deformability and availability of friction forces in movable bearing shoes. If such computations are not carried out, when used the movable bearing parts of roller or sector type as well as on the fluoroplastic gaskets, interrelation of the top can be ignored. In compression reinforced concrete members the minimum cross section area of longitudinal reinforcement, % to the full area of designed section of concrete should be not less than: 0.20- in members with flexibility lo / i ≤ 17; 0.60 - ditto, with flexibility lo / i ≥ 104; for intermediate values of flexibility - by interpolation (lo - designed length of member); i = √ Jb / Ab - radius of inertia of member cross section, where Jb - moment of inertia of concrete section; Ab - area of concrete section. If value of minimum reinforcing don’t satisfy the requirements then the structure members have to be designed as concrete. Flexibility of compression reinforced concrete members in any direction under stage of operation shouldn’t exceed 120 and under the stage of erection - 150. Flexibility lo / ief of members with indirect reinforcement shouldn’t exceed 55 in case of mesh and 35 in case of spiral, where ief - radius of inertia of concrete section part (limited by axes of end bars of the mesh or spiral).

3.17. Links of rectangular reinforced concrete pipes shall be computed as the closed loop frames with additional checking their webs by the scheme with rigidly embedded legs. Links of round reinforced concrete pipes can be computed only by bending moments (without consideration of longitudinal and transverse forces), determined by the Obligatory Appendix 12.

MATERIALS FOR CONCRETE AND REINFORCED CONCRETE STRUCTURES CONCRETE

GENERAL CHARACTERISTIC 3.18. *. The structures of bridges and culverts shall provide the use of structural heavy concrete of mean density 2200 to 2500 kg/m3, inclusive*, in conformity with GOST 26633-91. The concrete of other features and density can be applied in the pilot structures in the established order. * Norms and requirements described in the Section are referred to the concrete with given density, and further it calls to as “heavy concrete” (without density indication). The structure concrete as per compressive strength is characterized by the design class, transfer and yielding strengths. Compressive strength concrete class “B” is determined by the value guaranteed with probability 0.95, compressive strength checked on the cubes 150x150x150 mm in the installed periods. Design class “B” of concrete means strength of concrete for the structure that is designated for the project. The concrete transfer strength Rbp means strength of concrete (of relevant class) at the moment of force transfer to it in the process of manufacturing and erection (refer to item 3.31*). The yielding strength Rbo of concrete means strength of concrete (of relevant class) at moment of shipment (freezing) of concrete from the storage yard of the manufacturing plant.

3.19. *. Structures of bridges and culverts shall be made of the heavy concrete of compressive strength class B20, B22.51, B25, B27.51, B30, B35, B40, B45, B50, B55 and B60. The applied concrete should correspond to requirements given in Table 21* depending on type of the structure, its reinforcement and behaviour conditions.

SNiP 2.05.03-84 Page 52

In-situ casting of stressed reinforcement placed in open channels shall be carried out with the concrete not less than of class B30 as per compressive strength. The reinforcement channels in prestressed structures shall be injected with a mortar having strength of 28 days not less than 29.4 MPa (300 kgf/cm2). The joints of precast structures shall be in-situ casted with concrete of compressive strength class not lower than one accepted for butted members.

3.20. *. Grade F of concrete and mortar as per frost resistance depending on climatic conditions, region of construction, location and type of structure shall be specified following Table 22*.

3.21. . Frost resistance grade of concrete for pier bodies and facing blocks for bridges located near the hydraulic power station dams and water ponds shall be designated individually in each case on the base of investigation of certain conditions and requirements imposed in such cases to concrete material for the river hydraulic structures.

3.22. *. Concrete of grade W4 as per watertightness shall be used for submarine and underground structures not subjected to electric and chemical corrosion, according to SNiP 2.03.11-85. . Other members and parts of the structures, including concrete butt joints for reinforced concrete bridges and culverts, and protective layer of roadway floor shall be designed from concrete of grade not less than W6 as per watertightness. 1Concrete of class B22.5 and B27.5 shall be provided on condition that it will save cement quantity and will not spoil other technical-and-economical indices of the structure.

Table 21*

Type of structure, reinforcement and behaviour conditions Grade of concrete as per compressive strength, not less than

1. Concrete B20 2. Reinforced concrete , with stressed reinforcement, located 1: a) in zone of varying water level B25 b) in above-ground parts of the Work B22.5 c) in underground parts of the Work, as well as in the

cavities inside of precast-monolithic piers B20

3. Prestressed reinforced concrete: a) without anchors: - bar reinforcement of class: A-IV, Aт-IV B25 A-V, Aт-V B30 Aт-VI B35 -wire reinforcement : of single wires of class Bp B35 of single strands of class K-7 b) with anchors: wire reinforcement : of class B (outer or inner anchors) B25 of single strands, class K-7 of single tendons, class K-7 B35 of class K-7 strand tendons B35 steel wire ropes ( spiral twist, double and closed) B35 4. Facing blocks for piers on rivers with movement of ice when bridges are located in regions of mean ambient air temperature of the most cold five-day, °C: -40 and above B35

SNiP 2.05.03-84 Page 53

lower than 40 B45 1Characteristic of zone is indicated in remark1 and in notes to Table 22. In regions with mean ambient air temperature of the most cold five-day lower than -40°C, concrete of grade as per waterproofing not less than W8 shall be used in reinforced concrete piers in zone of varying water level of piers, in facing blocks and for all cases in regulating course of concrete of one- and two-course surfacing of roadway floor, applied as the waterproofing.

3.23. *Structure members intended to operate in corrosion medium require to be made of concrete and protective covers withstanding the corrosive action, in conformity with the requirements of SNiP 2.03.11-85. (Refer to Tables 22, 23)

Table 22* Location of the structures and their parts

in above-water, underground and above-ground unflooded zones 1

in zone of variable water level 2

concrete massive concr

ete massive

Facing blocks

Climatic conditions, characterized by mean month temperature of the most cold month in conformity of SNiP 2.01.01-82, °C

Type of structure reinforced concrete and thin-wall concrete (thickness not less than 0.5 m)

reinforced concrete and thin-wall concrete

placing of pier (concrete of outside zone)

placing to fill with facing blocks (concrete of inside zone)

Moderate: -10 and above 200 100 200 100 100 - Severe: lower than -10 up to

-20 including 200 100 300 200 100 300 Very severe: lower than -20 3000 200 300* 300 200 400** 1 The pier parts located 1 m above the ground surface are referred to the above-ground unflooded zones. For concrete of the pier parts located lower and achieving a half of the earth frost penetration depth there should be provided the requirements given for the structures located in the zone of the variable water level. 2 For the upper boundary of variable water level zone it shall be taken a conventional level, that is 1 m above of the highest ice movement level, for the lower one, a level 0.5 m down than the lower surface of the ice layer of the most low freeze-up. * Concrete of reinforced concrete members of intermediate piers of railway and combined bridges on stable water couгse in regions with very severe climatic conditions should be of F400 class as per frost resistance. ** Concrete of facing blocks of piers of large railway and combined bridges across the rivers with movement of ice more than 1.5 m thick and location of the bridge in the region of very severe climatic conditions should be of F500 class as per frost resistance. Notes: 1. Concrete of parts of underwater structures ( 0.5 m down than the lower surface of the ice layer of the most low freeze-up), underground structures (down than a half frost penetration depth) as well as being in permafrost soils shall be in conformity with the requirement as per frost resistance. In retaining-type abutments the underground parts of the structures are the parts of abutment body located lower than a half of a depth of frost penetration of soil in the cone of the fill. 2*. Concrete of all members of culverts, consolidation system of river beds and embankment cones, bank protection works and regulating structures (concrete located in season-melting layer of soil in permafrost regions), of all elements of the bridge road including slabs of roadbed part as well as concrete of the leveling layer of the roadbed pavement in function of waterproofing and the bridge road slabs of railway unballasted bridge should fit the requirements as per frost resistance for concrete located in zone of variable watewr level. 3*. When specifying the requirements as per frost resistance of bored piles areas the elevation 0.5 m down than the ice lower surface is accepted as the lower level of this zone.

Table 23*

SNiP 2.05.03-84 Page 54

Type of resistance Sym bol

Design resistance, MPa(kgf/cm2), concrete of class as per compressive strength

B20 B22.5

B25 B27.5

B30 B35 B40 B45 B50 B55 B60

Computation as per limit state of the first group Axial compression Rb 10.5 11.75 13.0 14.3 15.5 17.5 20.0 22.0 25.0 27.5 30.0 (prizm strength) (105) (120) (135) (145) (160) (180) (205) (225) (225) (280) (305) Axial tension Rb1 0.85 0.90 0.95 1.05 1.10 1.15 1.15 1.30 1.40 1.45 1.50 (8.5) (9.0) (10.0) (10.5

) (11.0)

(12.0) (13.0)

(13.5)

(14.0)

(14.5) (15.5)

Computations as per limit states of the second group Axial compression Rbser 15.0 16.8 18.5 20.5 22.0 25.5 29.0 32.0 36.0 39.5 43.0 (prizm strength) (155) (170) (190) (210) (225) (260) (295) (325) (365) (405) (440) Axial tension Rb1s

er 1.40 1.50 1.60 1.70 1.80 1.95 2.10 2.20 2.30 2.40 2.50

(14.5) (15.5)

(16.5) (17.5)

(18.5)

(20.0) (21.5)

(22.5)

(23.5)

(24.5) (25.5)

Shear when bending Rbsh 1.95 2.30 2.50 2.75 2.90 3.25 3.60 3.80 4.15 4.45 4.75 (20.0) (23.5

) (25.5) (28.0

) (29.5)

(33.0) (37.0)

(39.0)

(42.5)

(45.5) 48.5)

Axial compression (prizm strength) for computation to prevent longitudinal cracks formation in structure: at prestressing and erection Rb,m

c1 - - 13.7 15.2 16.7 19.6 23.0 26.0 29.9 32.8 36.2

(140) (155) (170) (200) (235) (265) (305) (335) (370) at operation Rb,m

c2 8.8 10.3 11.8 13.2 14.6 16.7 19.6 22.0 25.0 27.5 30.0

(90) (105) (120) (135) (150) (170) (200) (225) (255) (280) (305) Note. Values Rbser and Rb1ser equal to the rated resistances of concrete Rbn and Rb1n,, respectively.

Table 24 Factor stipulated introduction of coefficient of behaviour conditions Coefficient of

behaviour conditions Design resistance of concrete, to which coefficient is introduced

Value of coefficient

1. Multiple repeated load mb1 Rb as per i.3.26 2. Placing the concrete in vertical position of compressed members of cross section area 0.3 m2 and less

mb4

Rb

0.85

3. Impact of two-axial stressed state at cross stressing of concrete mb6 Rb, Rb,sh as per i.3.27 4. Behaviour of structure in regions with mean ambient air temperature of the most cold five-day lower than -40°C with absence of water saturation of concrete mb7 Rb 0.9 5. Alternative freezing and melting of concrete, located in water saturated state in structures operated in regions with mean ambient air

temperature of the most cold five-day, °C: -40 and above mb8 Rb 0.9 lower than 40 mb8 Rb 0.8 6. Behaviour of structures having no protection against solar radiation in

climatic subregion IVA according to SNiP 2.01.01-82 mb9 Rb, Rb1 0.85 7. Availability in composite structures: of joints to be concreted mb10 Rb As per i.3.28 Table 27 of glued joints mb10 Rb As per i.3.29 joints on mortar in unreinforced concrete masonry mb10 Rb As per i.3.30 8. Сalculation of members at the operation stage as per limit state of the

second group: a) for bevel bending and bevel eccentric compression mb13 Rb,mc2 1.1 b) for twisting mb14 Rb,sh 1.15 c) for shear on plane of joint of in-situ casting with concrete of the structure mb15 Rb,sh 0.5

RATED RESISTANCES 3.24. *. Different class concrete rated resistances when designed the bridge and culvert structures as per limit state of the first and second groups shall be taken by Table 23*. Rated resistances of concrete for indirect cut Rb,cut when designed the structures as per limit state of the first group shall be taken as follows:

SNiP 2.05.03-84 Page 55

for sections in cast-in-place reinforced concrete, when reinforcement behavior is ignored - R b,cut = 0.1 Rb; ditto, when reinforcement cutting behavior is included - by instructions of item 3.78*; in place of bonding the in-situ casting concrete to precast members concrete keeping the requirements of item 3.170 - R b,cut = 0.05 Rb. Designed compressive strength Rb and Rb,mc2 for concrete structures shall be taken 10 % lower than values given in Table 23*, and for indirect cut - Rb,cut = 0.005 Rb. Rated resistances of cast-in-place concrete of class B20 in internal cavities (in core) of round shells of piers can be increased 25% in calculations.

3.25. Rated resistances of concrete described in item 3.24* and Table 23*, in corresponding cases shall be accepted with a behavior conditions coefficient in accordance with Table 24. (Refer to Table 24)

3.26. *. With multiply repeated loads acting to members subjected to design for durability, the rated resistances of concrete to compression in designs of durability Rbf shall be determined by the formula: Rbf = mb1Rb = 0.6βbεbRb, (40) where mb1 - coefficient of behaviour conditions Rb - rated resistance of concrete to axial compression in designs of limit states of the first group (see Table 23*); βb - factor taking into account the time grain of strength in concrete and specified as per Table 25; εb - factor depending on asymmetry of cycle of repeated stresses

and specified by Table 26. Table 25

B27.5 B30 B35 B40 B45 B50 B55 B60 Grade of concrete as per compressive strength

and less

βb 1.34 1.31 1.28 1.26 1.24 1.22 1.21 1.20 Table 26

Coefficient of cycle of 0.1 0.2 0.3 0.4 0.5 0.6 repeated stresses ρb and less and more

εb 1.00 1.05 1.10 1.15 1.20 1.24 Note. With intermediate values ρb the coefficient εb shall be determined by interpolation

3.27. In calculations of prestressed structures when transfering the stress from reinforcing steel to the concrete with stress σby it is necessary to introduce a coefficient of behaviour conditions mb6 to design resistance of concrete against axial compression Rb , shear during bending Rb,sh , and indirect cut Rb,cut . It shall be equal to: a) for Rb

mb6 = 1.1 - if 0.1Rb ≤ σby ≤ 0.2Rb; mb6 = 1.2 - at stresses σby = 0.6Rb, that represent the maximum value taken into consideration in calculations; b) for Rb,sh and Rb,cut:

max,

min,

b

bbp

σσ

=

SNiP 2.05.03-84 Page 56

at σby ≤ 0.98 MPa (10 kgf/cm2); at σby = 2.94 MPa (30 kgf/cm2); for intermediate values σby the concrete behaviour conditions coefficients are specified by interpolation.

Table 27 Behaviour conditions coefficient mb10 with ratio Rbj/Rb,con Joint

thickness, mm 0.2 and less

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

From 20 to 40 0.70 0.6 0.82 0.88 0.94 1.0 1.0 1.0 1.0 70 0.50 0.58 0.65 0.72 0.80 0.85 0.90 0.95 1.0 200 and more 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.0

3.28. In design of the length-composite structures with butt joints filled with concrete the behaviour conditions coefficient mb10 values, taking into consideration different strength of concrete in the structure and in gap-filling material on each step of joint operation, shall be taken depending on the joint thickness b and the ratio of strength of concrete (mortar) in the butt (joint) Rbj to strength of concrete in blocks of the structure as per Table 27. When block parts are less than 120 mm thick, as well as in availability of holes in block body for insertion of stressed reinforcing bars, the values of mb10 for butt joint of 20-40 mm thick should be specified as for the joint 70 mm thick, and for the joint 70 mm thick - as for the joint of 200 mm thick.

3.29. Length-composite structure of bridge deck with glued butt joints shall be designed in such a way that be able to carry loads when glue is not still hardened. On designing the length-composite structures with glued butt joints the behaviour conditions coefficient mb10 , introduced to the rated resistance of concrete in blocks and taking into consideration strength structure decrease before glue, is hardened shall be specified depending on the block end faces concrete surface type: for waffled surface - 0.90, for smooth surface - 085. For glued butt joints which distance between each other is less than the maximum dimension of the section as well as for butts of inserted diaphragms the given values mb10 should be decreased by 0.05. For glued butt joints with hardened glue it should be specified mb10 =1. 3.30. . When designed unreinforced masonry of concrete blocks with the mortar the rated resistances of concrete, specified for concrete structures as per item 3.24* should include the coefficient of behaviour conditions mb10 equal to: - for blocks of concrete of class B20 and B22.5; 0.75 - for blocks of concrete of class B25 and B35; 0.70 - for blocks of concrete of class B40 and more. At this, the thickness of masonry joints shall not exceed 1.5 cm and the mortar in joints shall have the strength not less than 19.6 MPa (200 kgf/cm2) of 28-day age.

3.31. *. In manufacturing the prestressing structures the stressing of concrete is allowed with its strength not less than the established one for the design class. The concrete rated resistances for designation of the transfer strength shall be determined by the Table 23* by means of interpolation of the values referred to relevant classes of concrete.

,5.11,

6shb

by

b Rσ+=

shb

byb R

m,

6 5.11σ

+=

,1,

6shb

byb R

mσ

+=

SNiP 2.05.03-84 Page 57

The concrete strength to the moment of transfer of the complete force from the stressed reinforcement to the concrete and during the mounting shall be designated, as a rule, not less than corresponding to the class of concrete as per strength B25.

CHARACTERISTIC OF DEFORMABILITY PROPERTIES 3.32. *. The elasticity modulus values Eb of concrete in compression and in tension , and in hardening in the structures under natural conditions in case of experimental data lack shall be taken as per Table 28. The elasticity modulus values Eb given in Table 28, should be decreased by: 10% - for concrete subjected to heat-and-water treatment, as well as for concrete behaviour in conditions of alternating freezing and melting; 15% - for concrete of structures open to solar radiation in climatic sub-region IVA in conformity with the requirements of SNiP 2.01.01-82. For masonry of concrete blocks the deformation modulus values E shall be 0.5Eb - for concrete of classes B2—B35 and 0.6Eb - for concrete of classes B40 and above. The reduced deformation modulus of concrete of precast-monolithic pier as a whole is determined as weighted average as per modulus values of concrete deformation of block masonry and modulus of concrete elasticity of section core, taking into consideration proportionality of section areas in blocks in respect to the whole section area of the support.

Table 28

Class of con crete as per compression B20 B22.5 B25 B27.5 B30 B35 B40 B45 B50 B55 B60 Strength Eb-10-3, MPa 27.0 28.5 30.0 31.5 32.5 34.5 36.0 37.5 39.0 39.5 40.0 (kgf/cm2) (275) (290) (306) (321) (332) (352) (367) (382) (398) (403) (408) Concrete displacement modulus Gb shall be specified equal to 0.4 Eb., coefficient of lateral deformation (Poisson’s ratio) - ν = 0.2. The minimum value of elasticity modulus of glues used in butt joints of composite structures should be not less than 1500 MPa (15000 kgf/cm2), and lateral deformation coefficient value ν - not more than 0.25.

REINFORCEMENT 3.33. *. Quality of steel for reinforced concrete bridges and culverts reinforcement installed by the design depending upon the conditions of behaviour of construction members at average ambient air temperature of the most cold five-day in the region of construction shall be specified as per Table 29* taking into account the items 1.39, 3.91* and 3.133*, at this, sign “plus” means possible application of the given quality of steel in these conditions.

Table 29

Reinforcing-bar Steel Class Standard Quality Diameter

Members with Reinforcement not

Calculated for Durability

Members with Reinforcement Calculated for

Durability

Document of Steel mm

when structures are used in regions with mean ambient air temperature of the most cold five-day, °C

less -

40 -30 & more

less -30 up to -

40 including

less - 40

-30 &more

less -30 up to -

40 including

Rod, Hot-Rolled A - 1

GOST 5781-82, Ст3сп 6-10 + + + + + +

Smooth GOST 380-88* Ст3сп 12-40 + + + + + -

Ст3пс 6-10 + + + 1,2 +

+ 1 -

SNiP 2.05.03-84 Page 58

Ст3пс 12-16 + + 1 - + + 1 -

Ст3пс 18-40 + + 1

- +

1 - - Ст3кп 6-10 + - - - - - Rod, Hot-rolled,

GOST 5781-82, Ст5сп 10-40 + +

+ 1,2,3 + + -

Deformed Bars A-ll

GOST 380-88* Ст5пс 10-16 +

+ 1 - +

+ 1 -

ВСт5пс2 18-40 + - - +

1 - - Ac-ll 10ГТ 10-32 + + + + + +

A-lll 25Г2С 6-40 + + + 1 +

+ 1 + 1

35ГС 6-40 + + 4 - - - -

A-lV 20ХГ2Ц 10-22 + + + 5 + +

+ 5

A-V 23Х2Г2Т 10-32 + + + 5 + +

+ 5

Rod, Hard-heated AT-lV 6

GOST 10884-81 25Г2С 10-28

+ 5 + 5 + 5,7 - - -

10ГС2 10-18 + 5 + 5

+ 5,7 - - -

20ХГС2 10-18 + 5 + 5

+ 5,7 - - -

AT-V 6 20ХГС2 10-28 + 5 + 5

+ 5,7 - - -

AT-lV 6 20ХГС2 10-16 + 5 + 5

+ 5,7 - - - High-tension Wire, B

GOST7348-81 - 3-8 + +

+ 8 + +

+ 8

Smooth

High-tension Bp - 3-8 + + + 9 + +

+ 9

Deformed Wire Reinforcing Ropes K-7

GOST 13840-68 - 9-15 + + + + + +

Steel Ropes Spiral - - Provided + + - +

10 + 10

- by GOST with wire

Two- GOST3067-

88* of + + - +

10 + 10

-

strand GOST3068-

88* diameter lay 3 mm & more

Locked GOST3090-

73* Provided + + - +

10 + 10

-

Coil GOST7675-

73* by GOST

GOST7676-

73* 1 It can be used in tying frames and nets 2 It is not allowed to use for binders of span structures 3 It is not allowed to use, if dynamic coefficient exceeds 1.1 4 If dynamic coefficient exceeds 1.1, it can be used only in tying frames and nets. 5 Only as whole roads of measuring length 6 Hard-heated reinforcing steel only, if mark C (weldable) and K (corrosion crack resistant) can be applied. 7 It can be applied with guaranteed value of extension not less than 2 % 8 It can be applied with wire diameter 5-8 mm 9 It can be applied only with wire diameter 5 mm 10 It can be applied only in span structures of combined bridges On applicatijn of tensile principal reinforcement of different classes the strength designs should take into account:

SNiP 2.05.03-84 Page 59

- rated resistance corresponding to reinforcing steel of minimum strength - for untensioned reinforcement; - reinforcement of one quality only – for stressed reinforcement. Reinforcing steel of class A-II quality Cт5пc (semi-killed steel) can be used in decks (except stirrups) and in bridge piers if its rod diameter, mm not more than: 20 - for members with reinforcement that is not designed for durability;. 18 - ditto, with reinforcement designed for durability. The specified reinforcing steel with dia 22 mm and more can be used only in foundations and pier parts located beneath the half of the height of soil frost. Rod reinforcing steel thermally treated, high strength reinforcing wire, strands of class K-7 and steel wire ropes of spiral, twin-stranded and locked types are not allowed to be welded. It is prohibited to weld any detail or reinforcing bar to the rod stressed reinforcement located within the concrete body of the structure. As a principal (designed) reinforcement it is allowed to use new reinforcing steels including imported ones in the established order.

3.34. *. Loops for assembling shall be made of reinforcing steel of class A-1 quality Ст3сп (killed steel). If the project provides the structure erection at mean daily ambient air temperature not lower than -40°C, then loops for assembling can be made of reinforcing steel of class A-1 quality Ст3сп.

3.35. . Constructional reinforcement can be made of reinforcing steel of classes A-1 and A-II of quality indicated in Table 29*, as well as of deformed reinforcing steel wires of class Bp. (Refer to Table 29)

STEEL ARTICLES 3.36. *. The embedded members of expansion joints and other designed members shall use rolled stock as per GOST 7613-91: - quality of steel 16Д at designed temperature -40°C and higher; - quality of steel 15XCHД and 10XCHД at designed temperature lower than -40°C. Rolled stock of quality listed in GOST 19282-73* and GOST 19281-73 (except quality 17ГС and 17Г1С) not additionally heat-treated and not less than delivery category six can be used also. Rolled stock of thickness 4-24 mm of steel of quality Ст3пг as per GOST 535-88 can be used also at average ambient air temperature of the most cold five-day not lower than -30°C in the region of construction and with dynamic coefficient not more than 1.1 Rolled stock of quality Ст3cп (killed steel) with thickness 10-30 mm and Ст3пc with thickness 4-30 mm can be used at ambient air temperature of the most cold five-day more than -40°C. The embedded members not to be calculated for force actions can be made of rolled stock of quality Cn3кп (rimming steel). The Table 30 is excluded.

DESIGN CHARACTERISTICS OF REINFORCEMENT 3.37. *. Characteristic and designed tension resistances of reinforcing steel which can be used in reinforced concrete structures of bridges and culverts, should be specified as per Table 31*.

3.38. . Design compression resistance Rsc of untensioned reinforcing steel of class A-I, A-II, Ac-II and A-III shall be specified as equal to design tension resistances Rs. of this reinforcement. Applied in designs of structures as per limit states of the first group the maximum compression stresses Rpc in stressed reinforcement, located in zone of compression in member section and concrete-bonded, shall be specified not more than 500 MPa (5100 kgf/cm2).

SNiP 2.05.03-84 Page 60

COEFFICIENTS OF REINFORCEMENT WORKING MODE 3.39. *. When designed the reinforcement for durability (in railway bridge and separate bridge for underground railway) the rated resistances of reinforcing steel to tension for stresssed reinforcement Rsf and untensioned reinforcement Rpf shall be defined as per formula: Rsf = mas1 Rs = εpsβpwRs; (41) Rpf = map1 Rp = ερpβpwRp; (42)

Table 30 where mas1 , map1 - reinforcement behavior conditions coefficients taking into

consideration the influence of multiply repeated loads; Rs , Rp - rated resistances of reinforcing steel to tension specified as per

Table 31*; εps, ερp - coefficients depending on asymmetry of a cycle of stress change in

reinforcement p = σmin/σmax are given in Table 32*; βpwRs - coefficient, taking into consideration the weld joints influence on

behaviour conditions of reinforcing members or the influence of other parts welded to reinforcing members, is given in Table 33*.

Table 31 Design Strength of Extension in Calculating

Class of Reinforcing Diameter Characteristic Strength of

Extension Rsn and Rph Mpa as per Limit States of First Group

Bar Steel mm (kgf / cm 2 ) Rs and Rn and Rph MPa(kgf / cm 2 ) for Bridges and

Culverts

Railway Highway and City 1. Rod Reinforcement Untensioned Reinforcement

a) smooth A-1 6-40 235 ( 2400 ) 200 ( 2050 ) 210 ( 2150 )

b) deformed bars 10-40 295 ( 3000 ) 250 ( 2550 ) 265 (2700 ) A-ll, Ac-ll 6 and 8 390 (4000 ) 320 (3250 ) 340 (3450 ) A-lll 10-40 390 (4000 ) 330 (3350 ) 350 (3550 ) 2. Rod Reinforcement Stressted Reinforcement

a) hot-rolled A-lV * 10-32 590 ( 6000 ) 435 (4500 ) 465 (4750 ) A-V 10-32 785 (8000 ) b) hard-heated A-lV 10-28 590 ( 6000 ) - 465 ( 4750 ) A-V 10-14 785 ( 8000 ) - 645 ( 6600 ) 16-28 785 ( 8000 ) - 660 ( 6100 ) A-Vl 10-14 980 ( 10 000 ) - 775 ( 7900 ) 16 980 ( 10 000 ) - 745 ( 7600 )

3. High-tension Wire a) smooth B-ll 3 1490 (15 200 ) 1120 (11400 ) 1180 ( 12 050 ) 4 1410 ( 14 400 ) 1060 (10 800 ) 1120 ( 11 400 ) 5 1335 ( 13 600 ) 1000 (10 200 ) 1055 ( 10 750 ) 6 1255 (12 800 ) 940 ( 9600 ) 995 ( 10 150 ) 7 1175 ( 12 000 ) 885 ( 9000 ) 930 ( 9500 ) 8 1100 (11 200 ) 825 ( 8400 ) 865 (8850 ) b) defomed bars 3 1460 ( 14 900 ) 1100 ( 11 200 ) 1155 ( 11 800 ) 4 1375 ( 14 000 ) 1030 ( 10 500 ) 1090 ( 11 100 ) 5 1255 (12 800 ) 940 ( 9600 ) 995 ( 10 150 ) 6 1175 ( 12 000 ) 885 ( 9000 ) 930 (9500 ) 7 1100 ( 11 200 ) 825 ( 8400 ) 870 ( 8850 ) 8 1020 ( 10 400 ) 765 ( 7800 ) 810 ( 8250 ) 4. Reinforcing Ropes K-7 9 1375 ( 14 000 ) 1030 ( 10 500 ) 1090 ( 11 100 ) 12 1335 ( 13 600 ) 1000 (10 200 ) 1055 (10 750 ) 15 1295 ( 13 200 ) 970 ( 9900 ) 1025 ( 10 450 )

SNiP 2.05.03-84 Page 61

5. Steel Ropes with Spiral or As per 0.75 R rpn ( where R rpn is 0.54 R rpn 0.57 R rpn Two-strand Lay, and Relevant characteristic breaking strength Locked Coil Standards of rope as a whole )

* With mixed reinforcement the rod, hot-rolled reinforcement of class A - IV can be applied in function of untensioned of reinforcement. Note : 1. According to GOST 7348-81* plain wire of diameter 3-8 mm is of strength class from 1500 to 1100, and deformed wire of diameter 3-8 mm is of strength class from 1500 to 1000. 2. According to GOST 13840-68* reinforcing ropes K - 7 of diameter 9 - 15 mm of strength class from 1500 to 1400 (Tables 32*, 33*)

3.40. . When designed the tensioned transverse reinforcement (stirrups and bent bars) in inclined sections for the action of shear load the following reinforcement behavior conditions coefficients, indicated in Table 31*, .are introduced to the rated tension resistances of reinforcing steel ma4 = 0.8 - for rod reinforcement; ma4 = 0.7 - for reinforcement of high yield wire, strands of class K-7, and steel wire ropes of spiral and double twisted and of locked types. If in welded frames the diameter of stirrups from steel reinforcement of class A-III is less than 1/3 of longitudinal bar diameter, then accounted in design for shear strength the stresses in stirrups should not exceed , MPa (kgf/cm2): 245 (2500) - with stirrup diameter 6 and 8 mm; 255 (2600) - ditto, 10 mm and more.

3.41. *. For steel reinforcement of classes A-IV and A-V when using butt joints resistance-welded without mechanical dressing in lengthwise direction and butt joints on doubled offset straps the rated tension resistances, indicated in the Table 31*, must include reinforcement behavior conditions coefficient ma5 = 0.9. For steel reinforcement of classes A-I, A-II, Ac-II and A-III in availability of butt joints made by resistance welding, in welding bath on elongated or short straps, on doubled offset straps the rated tension resistances shall be taken the same as for the reinforcement steel without butt joints.

3.42. *. When designed the tensioned reinforcement as per strength in bent structures for reinforcing members (separate bars, tendons, wire ropes) located from the tension face of the member at a distance more than 1/5 of height of tension zone of section, the rated tension resistances of steel reinforcement as per Table 31* shall include the reinforcement behavior conditions coefficients

where h - x - height of tensile zone of section; - distance of tensile reinforcing member axis from the tensile face

of section.

3.43. *. With designs on the stage of preliminary stress formation in the structures, as well as on the stage of mounting the steel reinforcement rated resistances shall be taken with coefficients of behavior conditions equal to: 1,10 - for steel rod reinforcement as well as reinforcing members from high yield wire; 1.05 - for strands of class K-7 as well as steel wire ropes of spiral or twin-stranded or of locked type.

−−≥ )(1

xha

,15.01.16 ≤−

−=xh

ama

−−≥ )(51 xha

SNiP 2.05.03-84 Page 62

3.44. When steel wire ropes, swivel or double-twisted are bent around anchor semi-round blocks of dia not less than 24d (d-wire rope diameter) the rated tension resistances of wire ropes, when designed for strength, must include the wire rope behavior conditions coefficients ma10 that at a ratio D/d from 8 to 24 can be defined as follows:

When bending around blocks of dia D less than 8d, the coefficients of wire rope behavior conditions shall be specified as per experimental investigations results.

3.45. . With designs as per strength of zink-plated high-yield wire of class B-II of dia 5 mm the rated tension resistances of the wire as per Table 31* shall be added with reinforcement behavior conditions coefficients ma11, , equal to: 0.94 - with zinc-plating of wire as per group C, corresponding to middle corrosion conditions of medium; 0.88 - ditto, as per group Ж, corresponding to hard corrosion conditions of medium.

DESIGN CHARACTERISTICS FOR STEEL ARTICLES 3.46. . For reinforced concrete bridges and culverts steel articles representing their separate constructional parts (bearing parts, members of hinges and expansion joints, stop devices, etc.) and for steel embedded members from plates (sheets) and structural shapes the rated resistance shall be specified the same as for the members of bridge steel structures (see Section 4). Rated resistance for reinforcing bars anchored in concrete shall be specified according to instructions referred to the reinforcement.

CHARACTERISTIC OF REINFORCEMENT DEFORMABILITY PROPERTIES AND RATIO OF MODULUS OF ELASTICITY

Value of modulus of elasticity of reinforcement shall be specified as per Table 34. Table 34

Class (type) of reinforcing steel

Modulus of elasticity, MPa (kgf/cm2) of reinforcement

untensioned Es stressed Ep A-I, A-II, Ac-II 2.06x105(2.1x106) - A-III 1.96x105(2.0x106) - A-IV, Aт-IV, A-V - 1.86x105(1.9x106) Aт-V, Aт-VI - 1.86x105(1.9x106) B-II, Bp-II - 1.96x105(2.0x106) Parallel wire tendons, class B-II and Bp-II

- 1.77x105(1.8x106)

K-7 - 1.77x105(1.8x106) Tendons of strands K-7 - 1.67x105(1.7x106) Steel wire ropes: Spiral - 1.67x105(1.7x106) twin-stranded locked-type - 1.57x105(1.6x106)

3.47.

3.48. *. All members of the bridge designed by elastic body formulae, except bridges with reinforcement untensioned for durability and crack resistance, shall include the ratios of modulus of elasticity nl (Es/Ed or Ep/Eb) determined by values of modulus, given for reinforcement in Table 34 and for concrete in Table 28. In designs of bridge members with reinforcement untensioned for durability and crack resistance when determined the stresses and geometric characteristics of equivalent sections the area of

)43(10125.07.010 ≤+=dDma

SNiP 2.05.03-84 Page 63

reinforcement is considered with a coefficient for ratio of elasticity modulus n’ , at which the vibratory creep of concrete is taken into consideration. The values n’ should be specified as follows: 22.5 - with class of concrete B20 20 - ditto B22.5 and B25 17 - ditto B27.5 15 - ditto B30 and B35 10 - ditto B40 and above

ANALYSIS AS PER LIMITING STATES OF THE FIRST GROUP DESIGN AS PER STRENGTH AND STABILITY

GENERAL INSTRUCTIONS 3.49. . Concrete and reinforced concrete bridges and culverts shall be designed with the comparison of outside load designed forces with the limitting ones. Flexural, centre- and out-of centre tension concrete members are not allowed to use in the structures.

3.50. *. Designed forces in statically indeterminate structures should take into consideration re-distribution of forces from concrete shrinkage and creep, artificial regulation, crack formation and preliminary stress to the total force determined by characteristic values of the listed loads and forces, that is introduced with a safety factor 1.1 or 0.9.

3.51. . The limitting forces in structure members shall be determined in sections normal and inclined to longitudinal axis of the member.

3.52. *. When designed concrete and reinforced concrete members for action of compressive longitudinal force N, the least, produced from calculations of strength and stability, shall be taken as the designed value of the force. When designed as per strength it should be accounted a random eccentricity ec,c1 = 1/400 lo (lo is a member geometric length or its part between fixing points of member specified taking into consideration the requirements of item 3.16). When designed as per crack resistance and strains the random eccentricity shall not be taken into consideration. In members of statically determinate structures the eccentricity ec (relative to the gravity centre of equivalent section) is determined as a sum of eccentricities - determined by the static design of the structure and of random ec.c1’. For members of static indeterminate structure the eccentricity value of longitudinal force relative to the gravity centre of equivalent section ec is taken equal to the eccentricity, found from the static design, but not less than ec.c1’.

3.53. *. Strength and stability of compression, out-of-centre compression concrete and reinforced concrete members of rectangular, T-shaped, I-shaped and U-shaped sections in dependence on eccentricity value ec = M/N are designed according to Table 35*.

Table 35*

Structures concrete reinforced concrete Kind of design Number of items according to which the design should be

made, with eccentricities ec ≤ r ec > r ec ≤ r ec > r As per strength 3.68 3.68 3.69,б 3.70 3.54 3.54 - 3.54 As per stability 3.66 - 3.69,a - ___________________ 3.55 - 3.55 - Note. r – core distance

SNiP 2.05.03-84 Page 64

Compression members with designed initial eccentricity ec > r shall be designed to out-of-centre compression. The effect of deflection on increase of design force of out-of-centre compression member when designed as per undistorted scheme shall be taken into account by means of multiplying the eccentricity ec by a coefficient η determined as per item 3.54*.

3.54. *. The coefficient η taking into account the effect of deflection as per strength is determined as follows: where Ncr - conventional critical force, determined as follows: for concrete members

for reinforced concrete members

where Ib - inertia moment of concrete area, it is determined without taking into consideration the cracks in concrete; Is - inertia moment of concrete area of untensioned and stressed reinforcement. Inertia moments are determined relative to axes running through a gravity centre of equivalent section. In expressions (45) and (46) the coefficients ϕl and ϕp take into consideration the influence on deflection of long load action, preliminary stress of reinforcement and eccentricity relative value, respectively. The value of coefficient ϕ shall be taken equal to:

Where M - moment equal to the product of normal force N, of dead and live loads at a distance from place of force location N to the most tension bar (for concrete members - to the most tension face of section) or to the least compressed bar or face (with completely compressed section). The coefficient δ value shall be taken equal to ec/h, but not less than defined as follows:

where Rb - rated resistance of concrete, MPa; l0 - design length of member. If moments (or eccentricities) of complete load and of dead load have different signs, then with absolute value of eccentricity of complete load ec≤ 0.1 h it shall be taken ϕ = 1.0 and with ec< 0.1h it shall be taken ϕ = 1.05. Coefficient value ϕp taking into consideration the influence of preliminary tension of reinforcement against stiffness of the member shall be determined by formula

)44(,1

1

crNN

−=η

)45(,1.01.011.04.6

21

+

+=

δϕ o

bbcr l

IEN

)46(,1.01.0

11.04.62

+

++

= sl

p

l

b

o

bcr In

Il

EN

ϕδϕ

)47(,1MM l

l +=ϕ

)48(,01.001.05.0 0min bR

hl

−−=δ

)49(,121he

Rc

b

bpp

σϕ +=

SNiP 2.05.03-84 Page 65

where ϕbp - preliminary stress in concrete on the level of gravity centre of longitudinal reinforcement including all losses according to Obligatory Appendix 11; for annular and circular section h= D. In formula (49) the rated resistances Rb are specified without coefficients of concrete behaviour conditions and the values ec/h should not exceed 1.5. Compressed reinforced concrete members should have characteristics that ensure the condition N/Ncr ≤ 0.7 The members shall be designed for out-of-centre compression from the plane of flexure created by out-of-centre application of load taking into consideration a random eccentricity (see item 3.52*). For reinforced concrete members having immovable bearings or bearings identically moving during forced deformations (for ex. during temperature elongations), the coefficient value η shall be taken: for sections in the middle third of the member length - as per formula (44); ditto, within extreme thirds of the member length - by interpolation between values, calculated for the middle third and a unit taken for bearing sections.

3.55. *. The buckling coefficient ϕ when designed compressed (ec = 0) and out-of-centre compressed members having a relative eccentricity ec/r ≤ 1 shall be determined by formula:

Where ϕm - buckling coefficient taking into account an action of live load;

ϕl - ditto, for dead loads; N l - design longitudinal force from dead load taking into

account a force in stressed reinforcement, having no bond with concrete

Nm - design longitudinal force from live load; N= N L +Nm - tcomplete design longitudinal force. Coefficients ϕm and ϕl which calculations include also random eccentricity values as per item 3.52*, shall be specified for the reinforced concrete members as per Table 36, and for concrete members as per Table 37*.

STRENGTH DESIGN OF SECTIONS NORMAL TO LONGITUDINAL AXIS OF MEMBER 3.56. *. Limitting forces in sections according to items 3.62*-3.71* and 3.75 shall be determined on the basis of the following backgrounds: - concrete tension resistance is taken equal to zero; - concrete compression resistance is limited by stresses equal Rb and uniformly spreaded within conventional compression zone of concrete; - tension stresses in reinforcement are limited by rated tension resistances in untensioned Rs and stressed Rp reinforcement; - compressive stresses in untensioned reinforcement are limited by rated compression resistances Rsc, and in stressed reinforcement , by the most compressive stresses σpc according to item 3.60*; - when designed the section for general case as per SNiP 2.03.01-84* deformations (stresses) in reinforcement are determined depending on a height of compression zone of concrete taking into account deformations (stresses) of preliminary stresses. It is allowed when justified in established order to make calculations based on diagrams of deformation of concrete and reinforcement.

)50(,

NN

NN m

l

ml

m

+=

ϕϕ

ϕϕ

SNiP 2.05.03-84 Page 66

Note: For cases when rated resistances and stresses in concrete and reinforcement are substituted to formulae only in MPa, specialk instructions are given in the text. (Tables 36, 37)

Table 36

Characteristic for Member Buckling coefficients

Flexibility ϕ at relative eccentricities e c / r ϕ 1 l 0 / b l 0 / d l 0 / I 0 0,25 0,50 i,0

4 3,5 14 1 0,9 0,81 0,69 1 1 0,9 0,81 0,69

10 3,6 35 1 0,86 0,77 0,65 0,84 1 0,86 0,77 0,65

12 10,4 40 0,95 0,83 0,74 0,62 0,79 0,95 0,83 0,74 0,62

14 12,1 48,5 0,90 0,79 0,70 0,58 0,70 0,85 0,74 0,65 0,53

16 13,8 55 0,86 0,75 0,66 0,55 0,65 0,78 0,67 0,58 0,47

18 15,6 62,5 0,82 0,71 0,62 0,51 0,56 0,75 0,64 0,55 0,44

20 17,3 70 0,78 0,67 0,57 0,48 0,47 0,7 0,59 0,48 0,4

22 19,1 75 0,72 0,60 0,52 0,43 0,41 0,64 0,52 0,44 0,35

24 20,8 83 0,67 0,55 0,47 0,38 0,32 0,59 0,47 0,39 0,3

26 22,5 90 0,62 0,51 0,44 0,35 0,25 0,53 0,42 0,35 0,26

28 24,3 97 0,58 0,49 0,43 0,34 0,20 0,5 0,41 0,35 0,26

30 26 105 0,53 0,45 0,39 0,32 0,16 0,46 0,38 0,32 0,25

32 27,7 110 0,48 0,41 0,36 0,31 0,14 0,42 0,35 0,3 0,25

34 29 120 0,43 0,36 0,31 0,25 0,10 0,39 0,32 0,27 0,21

38 33 130 0,38 0,32 0,28 0,24 0,08 0,33 0,28 0,24 0,2

40 34,6 140 0,35 0,29 0,25 0,21 0,07 0,32 0,26 0,22 0,18

43 37,5 150 0,33 0,28 0,24 0,21 0,06 0,3 0,25 0,21 0,18

Note. Above the line there given values for reinforced concrete members with untensioned reinforcement and preliminary stressed with lack of concrete-to-steel bonding at the given stageof their behavior, beneath the line there given values

3.57. *. If in compression zone of design section the concretes are of different classes, then their areas are reduced proportionally to rated resistances to the concrete of one rated resistance.

3.58. . When designed the beam with a slab in compression zone the slab projections length introduced in the design should not exceed its six thicknesses h”ρ, counting from the beginning of projection and should be not more than a half of clearance distance between beams. The beginning of projection is taken from the beam rib or from the end of haunch if it has a slope 1:3 and more.

SNiP 2.05.03-84 Page 67

With variable thickness of slab as well as with haunches with slope less than 1:3 the projections length is determined by reduced thickness of the slab that is determined taking into consideration the area of the slab and haunches. The projection area of H-section tension chords is ignored when designed.

3.59. . If quantity of tension reinforcement as per constructional considerations or as per crack resistance design exceeds the one required as per strength design, then in the design it is permitted to account not all the reinforcement quantity but only the number required as per this design.

3.60. *. Stressed reinforcement located in compression zone and concrete-bonded shall be introduced into the design with a stress

where Rpc - taken in the design the largest compression stress in stressed reinforcement according to item 3.38; σpcl - designed stress in stressed reinforcement (with deduction of all losses) with load safety factor equal to γs =1.1; with σpcl ≤ Rpc it is taken σpcl = 0. Compressed reinforcement cross section area As’ is introduced in the design depending on ratio of designed height of concrete compressed zone x and distance as’ of this reinforcement to compressed face of section. When designed the bending elements the area As’ is taken into account completely if x2 ≥ 2as’, where x2 is a height of compressed zone determined taking into account compressed reinforcement As’. If not taking into account the compressed reinforcement a compressed zone of section responses to condition x1 ≥ 2as’, but taking into account the compressed reinforcement it responces to condition x1 < 2as’, then the strength design can be made using the condition

With x1< 2as’ As’ is ignored. 3.61. *. Sections, normal to longitudinal axis of member when outer force acts in the section symmetry axis plane and the reinforcement is concentrated near the member faces perpendicular to the given plane, shall be calculated depending on the value of relative height of compression zone ξ = x/ho= determined from corresponding conditions of equilibrium. The value ξ when designed the structures, shall not exceed, as a rule, a relative height of compression zone of concrete ξy with which the ultimate state of compression zone concrete takes place after achievement in stressed reinforcement of the stress equal to rated resistance Rs or Rp taking into account the corresponding reinforcement behavior conditions coefficients. The value ξy is determined by formula

where ω = 0.85 - 0.008Rb - for members with common reinforcement; ω = 0.85 - 0.008Rb+ δ ≤ 0.9 - for members with indirect reinforcement ; at this, the rated resistance of concrete Rb shall be taken in MPa and the value σ shall be equal to 10 µ but not more than 0.15 (where µ is reinforcement coefficient taken according to the item 3.72*); stresses in reinforcement σ1, MPa, shall be taken equal to: Rs - for untensioned reinforcement;

)51(,1pcpcpc R σσ −=

)52(),")(( sosspp ahARARM −+≤

)53(,)

1.11(1

2

1 ωσσ

ωζ

−+=y

SNiP 2.05.03-84 Page 68

Rp - 500 - σp - for stressed reinforcement; the stressed reinforcement rated resistance to tension Rp shall be defined taking into consideration the relevant coefficients of reinforcement behavior conditions and the prestressing value in the reinforcement σp shall be specified taking into consideration the first and the second losses as per Obligatory Appendix 11*. In availability of stressed and untensioned reinforcement the stress σ1 is taken as per stressed reinforcement; stress σ2 is the limited stress in compression zone reinforcement and shall be taken equal to 500 MPa. If, when designed the strength, it is necessary and reasonable to preserve the design-produced ξ = x/ho with value more than the boundary value ξy according to item 3.61*, then instructions of SNiP 2.03.01-84* are recommended to guide. Instructions of SNiP 2.03.01-84* are recommended to guide when designed the reinforced concrete members for bevel out-of-centre compression and bevel bend; members with reinforcement uniformly distributed by the section; short cantilevers, structures of punching and breaking, embedded articles, sling loops and members working for torsion bending and out-of-centre compression with torsion. Other methods for calculation of triangular, rhombus and other nonsquare sections including the reinforcement uniformly distributed and concentrated can be used if they are confirmed in the established order. Strength design of round sections of reinforced concrete members for out-of-centre compression is given in the recommended Appendix 29*. All mentioned above designs should use for concrete and reinforcement the rated resistances established in the present norms.

DESIGN OF FLEXURAL REINFORCED CONCRETE MEMBERS 3.62. *. Rectangular sections (dwg.2) shall be designed at

the base of : at this, height of compression zone x shall be determined as follows:

Dwg.2. Force and stress diagrams in section normal to centerline axis of flexural reinforced concrete member, when designed it as per strength. Here and in other formulas a height ho can be specified from resultant forces in reinforcement Ap and As. In absence of stressed reinforcement ho= h01. Strength of longitudinal joint of floor slab of ribbed span structures of highway and city bridges is designed by introducing into the formula (54), (55) right side the behavior conditions coefficients equal to 0.8 for deck less diaphragm and 0.9 for deck with diaphragm.

3.63. . T-section, H-section and box sections with a slab in compressed zone with

shall be designed depending on the position of compressed zone boundary: a) when compressed zone boundary runs in a slab (dwg.3,a) i.e. it is observed the condition

yhx

ζζ ≤=0 )54(),"(")"(")5.0( 0010 pppcsssrb ahAahARxhbzRM −+−+−≤ σ

)55("" bxRAARARAR bppcsscsspp =−−= σ

yhx

ζζ ≤=0

)56(""" ppcsscfbsspp AARxbRARAR σ++≤=

SNiP 2.05.03-84 Page 69

the calculation is made as for the rectangular section of width b’f in accordance with item 3.62*.; b) when compressed zone boundary runs in a rib (dwg.3,b), i.e. condition (56) is not observed, the calculation shall be performed on the base of:

at this, height of concrete compressed zone x can be determined by formula

Dwg.3. Form of compressed zone in the sections of reinforced concrete members with a slab in compressed zone a - when compressed zone boundary runs in a slab; b - ditto, in a rib.

3.64. . Flexural members of annular section, when ratio of internal and outer radii is r1/r2 ≥ 0.5, with reinforcement uniformly distributed by circumference length (with a number of longitudinal bars not less than six) shall be designed as for the out-of-centre compressed members in accordance with item 3.71*, replacing Necη by a value of bending moment M in formula (74*) and taking a value of longitudinal force N=0 in formulae (75*) and (76*).

3.65. *. If principal stressed reinforcement in flexural reinforced concrete members of highway bridges is not bonded to concrete then calculation of sections as per strength is performed according to items 3.62* and 3.63, at this, instead of the tension rated resistance of stressed reinforcement Rp it is introduced a value σp1 of established (minus all losses) preliminary stress in the stressed reinforcement. Besides that, the composed lengthwise structures shall be calculated by formulae of flexural material resistance against designed loads (with load safety factor) including the force of preliminary stress. All stages of behavior in joints not reinforced with untensioned reinforcement should exclude the tensile stresses in zones where these stresses originate from outer loads.

DESIGN OF ECCENTRICALLY COMPRESSED CONCRETE MEMBERS

3.66. . The eccentrically compressed concrete members with initial eccentricity ec ≤ r (see item .3.55* ) shall be calculated for stability keeping the condition

where ϕ - a coefficient specified as per item 3.55*; Ab - contracted section area of member.

3.67. *. The eccentrically compressed concrete members are designed at es > r (r is nugget distance as per the item .3.55*) depending upon the position of neutral axis and the value α determined as follows: α = αc - ecη , (60) where α - distance from point of application of longitudinal force N to the most contracted face of section taking into account the coefficient η, determined according to the item 3.54*; αc-- distance from the axis running through a centre of gravity of the whole section to the most contracted face ; ec - initial eccentricity of longitudinal force N relative to a centre of gravity of the whole section. At this, the resultant of external forces shall be within the cross section of the member with keeping the condition

)57(,)"(")"("

)"5.0(")"()5.0(

001

00

pppcsssc

fffbb

ahAahARhhhbbRxhbxRM

−+−+

+−−+−≤

σ

)58(")"("" ffbbppcsscsspp hbbRbxRAARARAR −+=−−= σ

)59(,bb ARN ϕ≤

SNiP 2.05.03-84 Page 70

When designed the eccentrically compressed concrete members of T-section, I-section and box section with a slab in the compression zone (dwg.No.4), the strength of section is ensured with keeping the condition

at this, compression zone height is determined : when α > 0.5h’f (neutral axis runs within the rib)

when α ≤ 0.5h’f (neutral axis runs within compression slab) the design uses the formulae (62) and (63) with replacing b for b’f. Dwg 4. Force and stress diagrams in the section normal to longitudinal axis of the eccentrically compressed concrete member. When designed the eccentrical members of rectangular section strength is ensured by keeping the condition

at this, the compressive zone height is determined as follows: Besides calculation as per strength in the plane of bending moment the member shall be checked by calculation as per stability with bending from the plane of moment action (See item 3.55*).

3.68.

DESIGN OF ECCENTRICALLY COMPRESSED REINFORCED CONCRETE MEMBERS

3.69. . Eccentrically compressed reinforced concrete members with designed eccentricity ec ≤ r (see item 3.55*) shall be calculated as per stability and strength on the base of the following conditions: calculation as per stability: in availability of reinforcement-to-concrete bonding

in absence of reinforcement-to-concrete bonding

b) calculation as per strength in availability of reinforcement-to-concrete bonding

in absence of reinforcement-to-concrete bonding In the formulae (66) - (69):

N - longitudinal compressive force of designed loads (without taking into account the preliminary stress forces);

)68(;'' 1 ppcsscbb AARARN σ−+≤

)69(;1

''' 1

scl

plbppcsscbb n

AnAARARN

µ

σσ

++−+≤

)61(,8.0 cc ae ≤η

)64(,bxRN b≤

)62(,")"( hbbRbxRN fbb −+≤

)63(;"

)"2)("(2

bh

habbaax fff −−++=

)65(2 ηcehx −=

)66(;)''( sscsscbb ARARARN ++≤ ϕ)67(;

1'

')'( 1scl

plbppcsscbb n

AnAARARN

µ

σσϕ

++−+≤

SNiP 2.05.03-84 Page 71

ϕ - buckling coefficient taken as per item 3.55*; Rb - rated tension resistance of concrete when designed as per strength, specified as per the Table 23; Ab - full area of member section (if reinforcement section area exceeds 3%, then Ab is replaced for Ab - A’s - A’p ); Rsc,Rpc - designed compression strength, taken as per i.3.38; σpc - stress in stressed reinforcement, located in compressive zone included in the design according to item 3.60*. σpc1 - steady-state preliminary stress in stressed reinforcement A’p, according to item 3.60*, after exposure of all losses;

A’s, A’p - section area of all untensioned and stressed reinforcement, respectively; n1 - ratio of modules of elasticity specified as per item.3.48*.

3.70. *. Strength of eccentically compressed reinforced concrete members of T-section, I-section and box cross sections with a slab in the compressive zone with eccentricity es > r at x > h’f and ξ ≤ ξy (dwg.3 and 5) shall be designed using the condition

and the value eo shall be determined by formula

where N - the longitudinal force; η - the coefficient determined by item 3.54*; e - distance from point of force application N to resultant of forces in tensile reinforcement; ec- initial eccentricity of longitudinal force N relative to the gravity centre of the whole section (taking into consideration random eccentricity as in the item 3.52*); σpc - compressive stress in stressed reinforcement, arranged in zone compressed by external load according to item 3.61*. For rectangular sections in formula (70) it is taken b’f = b. Dwg.5. Forces and stress diagrams in the section normal to longitudinal axis of the eccentrically compressed reinforced concrete member, when designed it as per strength. The height of concrete compresive zone x shall be determined by formula

Signs of forces in formula (72) correspond to position of force out of the section. When designed I-sections with a slab in tensile zone the slab projections are not considered. Besides the calculation as per strength in bending moment action plane it shall be carried out the calculation as per stability with a bending out of the plane of moment action. Behavior of compressed untensioned reinforcement shall be considered in accordance with item 3.60*. However, if, without taking into consideration this reinforcement, x > 2a’s but taking into

;'

b

sыс A

A=µ

;b

b AN

=σ

)70(,)'(')'('

)'5.0(')'()5.0(

001

000

pppcsssc

fffbb

ahAahARhhhbbRxhbxRNe

−+−+

+−−+−≤

σ)71(,)1(0 −+= ηceee

)72(')'(

''

ffbb

ppcsscsspз

hbbRbxRAARARARТ

−+=

=−−++ σ

SNiP 2.05.03-84 Page 72

consideration this reinforcement x < 2a’s ,then the strength design can be carried out using the condition

Design as per strength of eccentrically compressed prestressed members when preliminary stressed is replaced for the design under characteristic load as per formation of longitudinal cracks under characteristic load (item 3.100*) with limit of compressive stresses in concrete by values Rb;mc1, corresponding to class of transfer strength of the concrete.

3.71. *. Eccentrically compressed reinforced concrete members of annular section with a ratio of inner radius r1 and outer radius r2 as r1/r2 ≥ 0.5 with untensioned reinforcement equally spread over the circumference length (with a number of longitudinal bars not less than 6) are designed depending on the relative area of compressive zone of the concrete, equal to: Depending upon the value ξcir the designs use the reduced conditions:

a) with 0.15 < ξcir< 0.60 from condition of

b) with ξcir = 0.15 from condition of

where

with ξcir ≥ 0.6 from condition of

where

In formulae (74) - (79)* : Ab - area of the concrete of annular section; As,tot - area of section of all longitudinal reinforcement;

)73(,)'()( 00 ssspp ahNARARNe −++≤

*)74(7.2 ,

,

totssbb

totssсшк ARAR

ARNA

+

+=ζ

*)75(;3.12.0()7.11(

sin)( ,,0

circir

stotsscir

stotssmbbl rARrARZARN

ξξ

ππξ

−−

++≤

)76(,295.0sin)( ,,0 stotsscir

stotssmbbl rARrARrARN ++≤ππξ

*)77(;75.0

,

,

totssbb

totssсшк ARAR

ARNA

+

+=ζ

)78(,sin)( 2,0 π

πξсшкstotssmbbl rARrARN +≤

)79(,

2totssbb

сшк ARARN

+=ζ

SNiP 2.05.03-84 Page 73

rs - radius of circle running through the centre of gravity of bars of reinforcement under consideration. Eccentricity of longitudinal force eo is determined taking into consideration the member deflection in accordance with items Nos 3.52* - 3.54* and 3.70*. In designs of annular section members for mutual action of eccentric compression and bending with observance of given above requirements for the section when reinforcement is not stressed, it is possible to use the formulae (74)* - (79)* recommended for calculation of annular sections as per eccentric compression but taking into consideration the revised value of eccentricity eo caused by additional effect of summary bending moment M, taken by the resulting diagram of moments taking into consideration the location of forces caused the bending of the member. At this, the summarized value of eccentricity eo including into formulae (75)*, (76)* and (78)* for specific sections is determined taking into consideration summarized values of moments and normal forces for these sections. When defined the value of critical force Ncr entering the formula (44) to determine the coefficient η, taking into consideration the effect of deflection on the section strength it is necessary to take into account the coefficient value ϕ by formula (47). 3.72. *. The members of solid section with indirect reinforcing and with untensioned longitudinal reinforcement shall be designed according to requirements of items 3.69b and 3.70*. The design should include a part of concrete section limited with end bars of wire mesh of cross-section reinforcement or with a spiral (be counted by its axis) and substitute Rb in the design formulae by equivalent prizm strength Rb,red. Flexibility lo/icf of members with indirect reinforcement should not exceed 55 at reinforcing with wire mesh, 35 at reinforcing with spiral (where icf is a radius of inertia of a section part introduced into calculation). Formulae (80) and (81) are excluded. The value of Rb,red shall be determined as follows: when reinforced with cross welded wire mesh

where Rs - tension rated resistance of wire mesh reinforcement;

In formulae (82) and (83): nx,Asx,lx - respectively, number of bars, cross section area and wire mesh bar length, in one direction (be counted in axes of end bars); ny,Asy,Ty - ditto, in other direction; Aef - the section area of the concrete enclosed inside wire mesh contour (be counted by the axis of end bars); s - distance between wire meshes (be counted by axes of bars), if one wire mesh is placed, then the value s is taken equal to 7 cm; - coefficient of effectiveness of indirect reinforcing, determined as follows:

rrrrm

21 +=

)82(,,, sxysbredb RRR ϕµ+=

)83(sA

lAnlAn

cf

ysyyxsxxчбчн

+=µ

)84(23.0

1ψ

ϕ+

=

SNiP 2.05.03-84 Page 74

with

In formula (85) Rs and Rb are taken in MPa, µ = µs,xy. Cross-section areas of mesh bars as per unit of length in one and the other directions shall differ not more than 1.5 time; when reinforced with spiral or hoop reinforcement

where Rs - rated resistance of spiral reinforcement; ec - eccentricity of longitudinal force application (deflection effect is not considered); µ - reinforcement coefficient equal to:

As,cir - cross-section area of spiral reinforcement; def - diameter of part of section inside spiral; s - spacing of spiral. When the effect of deflection on the carrying capacity of members with lateral reinforcement is taken into consideration it is recommended to follow the instructions of item 3.54*, determining the inertia moment for part of their section defined by end bars of meshes or enclosed inside the spiral. The value Ncr produced by formula (45) shall be multiplied to the coefficient (where cef is equal to the height or to the diameter of considered concrete section part), and when

determined δ, the second member of right part of formula (48) is replaced with

(where Lateral reinforcement is considered in the design on condition that carrying capacity of the member determined with account of Acf and Rb,red exceeds its carrying capacity determined by the total section Ab and with account of Rb (but without lateral reinforcement). Besides, the lateral reinforcement should correspond to constructional requirements of item 3.153.

3.73. *. When calculated the members with lateral reinforcement the strength design shall be accompanied with the design ensuring the crack resistance of the concrete cover to reinforcement. The latter shall be made according to the instructions of items 3.69,b and 3.70* under performance load (at γ=1), taking into account the total section area of the concrete and taking instead of Rb and Rs the rated resistance Rbn and Rsn for limit states of the second group as well as taking the reinforcement compression rated resistance equal to Rsc,ser but not more than 400 MPa.

)85(10+

=b

s

RRµ

ϕ

)86(5.71(2,ef

csbredb d

eRRR −+= µ

)87(4 ,

sdA

ef

cirs=µ

105.025.0 01 ≤+=

efcl

ϕ

2001.0 ϕefcl

).111.0 02 ≤−=

efcl

ϕ

SNiP 2.05.03-84 Page 75

DESIGN OF CENTRALLY TENSIONED MEMBERS 3.74. When designed the section of centrally tensioned reinforced concrete members the reinforcement should take up completely all the design force, at this, it is required to follow the condition N ≤ RsAs + RpAp (88) where N = longitudinal tensile force applied centrally

DESIGN OF ECCENTRICALLY TENSIONED REINFORCED CONCRETE MEMBERS 3.75. Sections of eccentrically tensioned reinforced concrete members shall be designed depending on the position of longitudinal force N and under the following conditions: a) when longitudinal force N is applied between the resultants of forces in the corresponding reinforcement (dwg.6, a), at this, the whole section is tensioned, then in this case the reinforcement shall take up all designed force and calculation is made using the condition:

b) when longitudinal force N is applied outside the distance between the resultants of forces in the corresponding reinforcement (dwg.6,б) with location of neutral axis within a rib, then the section rigidity shall be established under the condition

The height x of the concrete compressive zone is determined as per formula Dwg. No. 6. Diagram of forces and diagram of stresses in the section normal to longitudinal axis of eccentrically tensioned reinforced concrete member, when it is designed as per strength a – longitudinal force N is applied between the resultants of forces in the reinforcement; б – ditto, outside the distance between the resultants of forces in the reinforcement. If value calculated from Formula 92 is x >ξyh0, then x =ξyh0, is inserted into condition of (91) where ξy is determined according to instructions of item 3.61*. Compression reinforcement behavior shall be accounted according to instructions of item 3.60*. However, in case the value is x > 2a’s when reinforcement behavior is not taken into consideration, but x <2a’s when reinforcement behavior is taken into consideration , then the strength shall be designed from the condition

DESIGN AS PER STRENGTH OF SECTIONS INCLINED TO LONGITUDINAL AXIS OF MEMBER

3.76. *. Strength of inclined sections shall be designed with allowance for variability of section: to the action of shear force between inclined cracks (see item 3.77*) and by the crack inclination line (see item 3.78*); to the action of bending moment by crack inclination line for transverse-reinforced members (see item 3.83*).

)93()")(( sosspp ahNARARNe −−+≤

)90();()('

)89();()(''

'0

''01

'

ppppssss

pppsss

aahARaahARNe

ahARahARNe

−−+−−≤

−+−≤

)91();()(

)5.0()()5.0('

0''

01'

'0

1'0

pppcsssc

fffbb

ahAahARhhhbbRxhbxRNe

−+−

+−−+−≤

σ

)92()( ''

''

ffbb

ppcssssspp

hbbRbxR

NAARARAR

−+=

=−−−+ σ

SNiP 2.05.03-84 Page 76

DESIGN OF SECTIONS INCLINED TO MEMBER LONGITUDINAL AXIS FOR ACTION OF SHEAR FORCE

3.77. *. For reinforced concrete members with transverse reinforcement it should be observed the condition ensuring the compressed concrete strength between inclined cracks:

In Equation (94) Q – shear force at a distance not less than ho from support axis; ϕw1 = 1+ηn1µw, when stirrups are located normally to longitudinal axis ϕw1≤1.3, where η= 5 – when stirrups are normal to longitudinal axis of member; η= 10 - ditto, inclined at an angle of 45’; η1 – ratio of coefficients of elasticity of reinforcement and concrete, determined as per item 3.48*; Asw – section area of stirrup branches, located in one plane;

Sw – distance between stirrups as per a normal to them; b – depth of web (rib); ho – working height of section. The coefficient ϕb1 is determined by equation ϕb1 =1-0.01Rb, where rated resistance Rb is taken in MPa.

3.78. *. Inclined sections of members with transverse reinforcement are designed to the action of shear force (Dwg.7) by the following conditions: for members with untensioned reinforcement

for members with stressed reinforcement in availability of untensioned stirrups

Dwg. No.7. Diagram of forces in sections inclined to longitudinal axis of reinforced concrete member, when designed it as per strength for action of shear force a – with untensioned reinforcement; b - with stressed reinforcement In Equations (95) * and (96)*: Q – maximum value of shear force from external load located to one side from inclined section under consideration; ∑RswAsisinα, - sums of forces projections of all crossed untensioned (inclined and normal to l∑RswAsw longitudinal axis of member) reinforcement with a of section projection length c not exceeding 2ho; ∑RswAp1sinα, - ditto, in stressed reinforcement, bonded to concrete (if stressed bars are not l∑RswAsw bonded to concrete, then the rated resistance value Rpw shall be taken equal to steady preliminary stress σpw1 in stressed reinforcement); Rsw, Rpw - rated resistance of untensioned reinforcement and stressed reinforcement taking into consideration coefficients mo4 or mp4, determined by item 3.40; α - angle of bars (tendons) inclination to longitudinal axis of member in place of crossing the inclined section;

wbSswA

wμ =

*)95(;sin rwbswswsisw QQARaARQ ++∑+∑≤

*)96(;sin rwbpwipwswswpipw QQARARaARQ +∑+∑+∑≤

)94(3.0 011 bhRQ bbw ϕϕ≤

SNiP 2.05.03-84 Page 77

Qb - shear force transmitted in design to compression zone concrete above the end of inclined section and determined by Equation

where b,ho - depth of a web (rib) or width of solid slab and effective height of section crossing a centre of inclined section compression zone. c - length of projection of noneffective inclined section to longitudinal axis of member that is defined by comparative calculations according to the requirements of item 3.79*. m - behaviour conditions coefficient equal to:

but not less than1.3 and not more than 2.5. where Rb,sh - rated resistance for shear during bending (Table 23*); τq - the most shearing stress from standard load; at τq ≤ 0.25Rb,th it is allowed not to check for strength by the inclined sections, but at τq > Rb,th the section shall be re-designed; Qw

r - force taken up by horizontal reinforcement, kgf: Qw

r = 1000 Awr K (99)*

where Awr - area of horizontal stressed reinforcement and untensioned reinforcement, cm2,

that is crossed with inclined section at an angle β, in degree. Coefficient K value is determined by the condition:

In sections located between stirrups, with β = 90° Qw

r = 1000 Awr

3.79. *. The most disadvantage inclined section and corresponding projection to the member longitudinal axis shall be defined by means of comparative calculations from the condition of minimum of shear force taken up by concrete and the reinforcement. At this, at sections of 2ho long from abutment section it should be checked the inclined sections with angle of inclination to abutment (vertical) section 45° for structures with untensioned reinforcement and 60° - for structures with stressed reinforcement. With concentrated load action near the pier the most dangerous inclined section has direction from load to the pier.

3.80. . In availability of stressed stirrups the angle to the member longitudinal axis when additionally checked by inclined sections shall be determined by Equation: where σmt - the value of main tensioning member; τb - the value of tangential stress.

3.81. *. For reinforced concrete members having no transverse reinforcing bars it should be observed the condition

*)97(2 2

obtobt

b bhmRc

bhRQ ≤+

=

*)98(,14.03.1 ,

−+=

q

shbRm

τ

*)100(140

500 ≤°

°−==

βK

,b

mtrctgτ

σαα =

SNiP 2.05.03-84 Page 78

Q ≤ Q+ Qwr (101)*

which constrains the inclined cracks development.

3.82. . When designing tensile and eccentrically tensile members having no compressive zone in them, all shear force Q shall be taken up by transverse reinforcement. When designing eccentrically tensile members in availability of compressive zone the value Q calculated by Equation (97)* shall be multiplied to coefficient kr equal to:

but not less than 0.2 (N- longitudinal tensional force)

DESIGN OF SECTIONS, INCLINED TO MEMBER LONGITUDINAL AXIS, FOR ACTION OF BENDING MOMENTS

3.83. .* Inclined sections by bending moment (Dwg.8) shall be designed using the conditions: for members with untensioned reinforcement

for members with stressed reinforcement in availability of untensioned stirrups M ≤ RpApzp + Σ RpApwzpw + Σ RsAswzsw + Σ RpApizpi (104) where M - moment relative to an axis, running through centre of inclined section compressive zone, from design loads located in one side direction of the compressed end of section; zsw,zs,zsi - distances from forces in untensioned reinforcement and stressed reinforcement up zp,zp,zpi to the point of resultant forces in compressive zone of concrete in section, for which the moment is defined; the other designations are given in item 3.78*. Longitudinal reinforcement of webs is not considered in the design. Position of disadvantage inclined section shall be determined by means of comparative calculations made, as a rule, in place of break or bar bending and in place of sharp section change. Dwg. No.8. Diagram of forces in section, inclined to longitudinal axis of reinforced concrete member, when its strength is designed against action of bending moment. a – with untensioned reinforcement ; b – with stressed reinforcement

3.84. *. For inclined sections crossing the tensile face of the member on parts supported against formation of normal cracks from rated load (at σbt < Rbt), the moment action design can be ignored.

3.85. *. When strength is designed against the moment action the stressed transverse reinforcement having no bonding to concrete shall be taken into consideration the same way as in design for shear force according to item 3.78*.

BUTT JOINTS DESIGN FOR SHEAR 3.86. *. Glued or concrete joints (flat or with a step) in bent length-composite structures shall be designed for strength against shear as follows: Q ≤ 0.45 mshNα’ (105) Where Q - maximum shearing force against outside loads and preliminary stress in inclined reinforcement taken with coefficients of reliability corresponding to calculations as per the first group of limiting states; 0.45 - designed value for coefficient of concrete-to-concrete friction ; msh - behavior conditions coefficient of butt joint when sheared, determined for different kinds of joints according to item 3.87*;

)102(,2.01obtbhR

Nk −=

)103(;isissswswssssss zARzARzARM Σ+Σ+≤

SNiP 2.05.03-84 Page 79

Nα’ - force taken by joint net section corresponding to compressive part of normal stresses diagram. At this, coefficients of reliability for forces originating in stressed reinforcement (instead of indicated in Table 8* and item 2.5) are taken equal to: γ = 1 ±0.1 - at a number of tendons (bars) under tension

Butt joint net section includes the section of a web (rib) and its continuation in the upper and lower slabs. When butt joint has been crossed within the web by inclined tendons located in closed grouted channels the joint net section can include also web-adjacent parts of haunches and a slab with a length each side not more than two thickness of the slab (less haunches) or the web if it is thinner than the slab. When considering shear combined behavior of the glued joint and rigid members (steps, keys, etc.), taking up shear force, the bearing capacity of rigid members shall be taken with combination factor equal to 0.7. At this, force taking up by a rigid member should not exceed a half of the value of shear force acting to the joint.

3.87. *. Behavior conditions coefficient msh in Equation (105) shall be taken as equal to : 1.2 for glued dense thin joint, with hardening the glue; for concrete joint less reinforcement free lengths ; 0.25 for glued joint with non-hardened glue, with smooth surface of block ends; 0.45 ditto, with riffle surface of block ends.

3.88. *. Joints of length-composite decks don’t permit elongating stresses from design dead loads considering in calculations as per the first group of limiting states.

LOCAL COMPRESSION (BEARING STRESS) DESIGN 3.89. *. Local compression (bearing stress) design of members without indirect reinforcement shall satisfy the condition:

where N - longitudinal compressed force from local load; ϕloc - coefficient taken equal to 1.00 - if local load is uniformly distributed on bearing stress area ; 0.75 - if local load is not uniformly distributed on bearing stress area. Aloc - bearing stress area Rb,loc – concrete rated resistance to bearing stress determined as follows: Rb,loc = 13.5 ϕloc1Rbt; (107)

In Equations (107) and (108): Rbt - rated resistance of concrete to elongation for concrete structures; Ad - effective area symmetrical in respect to bearing stress area in accordance with layouts given in Dwg.9.

109

1.0110 >−

+=≤ ∫ natn

andn γ

)106(,, loclocbloc ARN ϕ≤

*)108(231 ≤=loc

dloc A

Aϕ

SNiP 2.05.03-84 Page 80

3.90. . *. Local compression (bearing stress) design of members with indirect reinforcement in the form of welded crosswise wire mesh shall satisfy the condition:

where Aloc - bearing stress area; Rb,red - concrete strength reduced to axial compression, determined by Equation: Rb,red = Rbϕloc,b + ϕµRsϕloc,s (110) In Equation (110): Rb, Rs in MPa; ϕ, µ - relatively, coefficient of efficiency for direct reinforcement and coefficient of section

reinforcement with meshes or spirals (Equations (83), (84) and (87) according to item 3.72*. Dwg No.9. Layouts of effective areas Ad depending on position of bearing stress areas Aloc

Aef - area of concrete enclosed inside direct reinforcement wire meshes counting them by end bars, at this the condition Aloc < Aef ≤ Ad shall be satisfied. Ad - effective area symmetrical in respect to the bearing stress area Aloc and accepted not more than indicated in Dwg.9. Other symbols shall be specified according to the requirements of item 3.89*. Structure concrete in zone of transmission to it of concentrated forces (see Dwg.9.) shall be rated to local compression (bearing stress) as well as per crack resistance with allowance of local elongating stresses according to instructions of item 3.111*.

ENDURANCE DESIGN 3.91. *. Design for endurance shall be executed for members of railway bridges, bridges for underground railways, combined bridges and slabs of roadway part of motor and city bridges; with backfill less than 1 m thick – for frame cross-bars and floors of rectangular reinforced concrete culverts, including places of their connection with walls. Endurance is not designed for:

- supports made of concrete - foundations of all kinds; - links of round pipes; - rectangular pipes and their floors with backfill l m thick and more; - webs of beams of decks; - concrete of elongated zone; - reinforcement acting only for compression; - reinforced concrete piers where asymmetry coefficient of stress cycle exceeds 0.6 in

concrete and 0.7 in reinforcement. If when designed the endurance of reinforced concrete piers and pipe floors the strains in

reinforcement don’t exceed 75% of established rated resistance (taking into consideration coefficients of behavior conditions according to item 3.26* and 3./39*) then additional limits for reinforcement classes and steel quality indicated in item 3.33* for reinforcement, rated to durability at ambient air mean temperature of the most cold five days below -40°C can’t be done.

)109(,, locredb ARN ≤

33, ≤=loc

dbloc A

Aϕ

;5.35.4,ef

locsloc A

A−=ϕ

SNiP 2.05.03-84 Page 81

3.92. *. Members (or their parts) of prestressed reinforced concrete structures referred to categories of requirements as per crack resistance 2a or 2б (see item 3.95*), as per sections normal to longitudinal axis, shall be designed for durability by Equations given below, substituting the absolute values of stresses and taking the member sections without cracks: a) when designed the reinforcement of tensile zone:

b) when designed the concrete in compressive zone of bending, eccentrically compressed and eccentrically tensile members:

(sign of stresses when designed the statically indeterminable constructions can change into opposite one).

In Equations (111-114): σp,max, σp,min - stresses in stressed reinforcement, maximum and minimum,

respectively; σp1 - steady preliminary stresses (deduction of losses) in stressed reinforcement of tensile zone; σel,c - decrease of stress in stressed reinforcement of tensile zone from elastic stressing of concrete in accordance with item 3.93; σpg = n1σbrg - reinforcement stresses from dead load; σpv = n1σbrv - reinforcement stresses from live load; where n1 - ratio of elasticity modulus in accordance with item 3.48*;

map1 - behavior conditions coefficient of reinforcement considering multiply repeated action of load in accordance with item 3.39; Rp - rated resistance of stressed reinforcement according to item 3.37*; σbc,max’, σbc,min - compressive stresses in concrete, maximum and minimum, respectively; σbc1 - steady (deduction of losses) preliminary stresses in concrete of compressive zone; σbrg, σbev - concrete stresses from dead load tensile and compressive zones, respectively; mbl - behavior conditions coefficient of reinforcement considering multiply repeated action of load in accordance with item 3.26*; Rb - rated resistance of concrete to compression according to item 3.24*. Notes. When designed both the durability and crack resistance, when stresses in concrete are determined taking into consideration the reduced section, Equations use the stresses in reinforcement tensioned to thrusts without their decrease from elastic stressing of concrete (provided that all reinforcement having bonding to concrete is included into characteristic of section when designed).

3.93. Stresses in stressed reinforcement shall be calculated taking into consideration decrease from elastic stressing of concrete σei,c, that, at simultaneous stressing of concrete of all reinforcement tensioned to thrusts, shall be determined as:

σei,c = n1σbp (115) When stressed the reinforcement to concrete in several steps a decrease of preliminary stress in reinforcement tensioned before shall be determined as follows:

)112(;)(

)111(;)(

,1min,

,1max,

pgcetpp

paptpvpgcelpp Rm

σσσσ

σσσσσ

+−=

≤++−=

)114(

)113(;

1min,

11max,

begbebc

bbbevbcgbcbc Rm

σσσ

σσσσ

+=

≤++=

SNiP 2.05.03-84 Page 82

σei,c = n1∆σbm1 (116) In Equations (115) and (116): n1 - ratio of elasticity modulus in accordance with item 3.48*; σbp - preliminary stress in concrete at a level of gravity centre of stressed reinforcement caused by stressing of all reinforcement section; ∆σb - preliminary stress in concrete at a level of gravity centre of stressed reinforcement caused by tension of one tendon, taking into account the losses corresponding to the given step of work; m1 - number of similar tendons (bars) tensioned after that tendon (bar) for which losses of stresses are under determination.

3.94. *. Endurance of reinforced concrete structure members with untensioned reinforcement is designed by formulae of materials resistance not taking into account the behavior of concrete in tensile zone. It can be designed by formulae indicated in Table 38*. The left parts of formulae in Table 38* can be used to determine the values σmin and σmax when calculated the coefficient p given in Tables 26, 32* and 33* . In calculation by formula (121) it shall be taken into consideration the instructions in item 3.91* about the design of endurance also of preferably compressive reinforcement at alternate stresses. Eccentrically elongated members can be designed the same way. When designed the centrally elongated members all tensile force is transferred to the reinforcement. Besides endurance the sections shall be designed as per strength.

Table 38*

Member behavior characteristic Formula for design Bending in one of main planes: check as per concrete check as per reinforcement

M ---- x’≤ mb1Rb (117) Ired M n’--- (h -x’- α)≤ mαs1Rs (118) Ired

Axial compression in concrete N ---- ≤ mb1Rb (119) Ared

Eccentric compression : check as per concrete check as per reinforcement

σb ≤ mb1Rb (120)* σs ≤ mas1Rs (121)*

In Equations (117) - (121)*: M, N - moment and normal force; Ired - equivalent section neutral moment of inertia not taking into consideration elongated zone of concrete with introduction of ratio n to all reinforcement area according to item 3.48*. x’ - lift of the concrete compressive zone determined by formulae of elastic body not taking into consideration tensile zone of concrete; mb1, mas1 - coefficients taking into consideration asymmetry of stress cycle in concrete and in untensioned reinforcement (taking into consideration welded joints), according to items 3.26* and 3.39* introduced to rated resistance of concrete Rb and reinforcement Rs, respectively; Ared - member equivalent cross-section area with introduction of ratio n, according

SNiP 2.05.03-84 Page 83

to item 3.48* to all reinforcement cross-section area.

ANALYSIS AS PER LIMITTING STATES OF THE SECOND GROUP CRACK RESISTANCE DESIGN

GENERAL 3.95. *. Reinforced concrete structures of bridges and culverts depending on their type and purpose, the applied reinforcement and behavior conditions shall satisfy to categories of requirements as per crack resistance given in Table 39*. Crack resistance is characterized with values of tensile and compressive stresses in concrete and with designed crack width Calculations on determination of stresses in concrete, crack formation and crack width determination shall be made taking into consideration the preliminary stress losses in reinforcement, according to Obligatory Appendix 11*. Composite prestressed structures of bridges of all purposes don’t permit the origin of tensile stresses in compressed joints, as well as in members of through spans of railway bridges. In length-composite span structures of bridges minimum compressive stresses in concrete with participation of created designed dead load shall comply with the category of requirements as per crack resistance 2б. In continuous deck structures composed of sectional prestressed beams with elevated unstressed concrete cast joints reinforced with untensioned reinforcement the width of cracks in concrete under the designed load shall comply to category of requirements 3.

3.96. *. In highway and city bridges when applied mixed reinforcement the limiting tensile stresses in concrete can be increased up to 2 Rbt,ser provided that all force from the part of epure of tensile stresses originating on that part of section area where tensile stresses exceed 1.4 Rbt,ser, is taken up only by untensioned reinforcement. Besides that, cross crack width shall be designed following the instructions of items 3.108* and 3.109*.

SNiP 2.05.03-84 Page 84

Table 39* Type and purpose of structure, specific feature of reinforcing

Category of requirement as per crack resistance

Limiting values

Tensile stresses in concrete

Designed width of crack opening , ∆σ

Minimum compressive stresses in absence of live load.

Railway bridges (except span beam webs) members reinforced with stressing steel wire mesh of all kinds

Highway and city bridges members (except span beam webs) reinforced with stressing high-tensile wire 3 mm in dia, strands of class K-7, 9 mm in dia, as well as stressing steel wire ropes ( spiral, twin stranded and lock)

Railway bridges members (except span beam webs) reinforced with stressing reinforcing bars.

Highway and city bridges members (except span beam webs) reinforced with stressing high-tensile steel wire

4 mm and more in dia, stressing rstrands of class K-7,12 and 15 mm in dia.

Piles of bridges of all purposes reinforced with stressing reinforcing bars and stressing high-tensile steel wire 4 mm and more in dia, as well as stressing strands of class K-7

Webs (ribs) of bridge prestressed span beams when designed for main stresses.

Highway and city bridges members reinforced with stressing reinforcing bars

Members parts (in bridges of all purposes) calculated for local stresses in zone of arrangement of stressing steel wire reinforcement.

Members of bridges and culverts of all purposes with untensioned reinforcement.

Reinforced concrete members of bridges of all purposes with stressed reinforcement, located outside the member body.

Members parts (in bridges of all purposes) calculated for local stresses in zone of arrangement of stressed reinforcing bars.

2a

2б

3a

3б

3в

0.4 Rbt,ser

1.4 R*bt,ser

By Table 40*

-

-

-

0.015**

0.015

0.020

0.030***

--

Not less than 0.1Rb with concrete class B30 and less, and not less than 1.6 MPa (16.3kgf/cm2) with concrete class B35 and more

-

-

-

SNiP 2.05.03-84 Page 85

* Mixed reinforcement permits to increase the limiting tensile stresses in concrete according to instructions of item 3.96*. In highway and city bridge structures with stressing steel wire reinforcement when it is located in the roadway slab the limiting tensile stresses in concrete in direction of its compressing should be not more than 0.8 Rbt,ser. ** Zink-plated wire permit to take ∆cr = 0.22 cm *** Crack opening width should not exceed in cm: 0.020 in railway bridge span members, in highway and city bridge roadway upper slabs with arranging waterproofing on them, in legs and piles of all piers located in alternate water level zone as well as in members and parts of culverts; 0.015 in railway bridge intermediate supports in zones located above and beneath alternate water level ; 0.010 at a level of the upper face in longitudinal joints of upper slabs of the roadway of highway and city bridges. When bridges and culverts are located near the dams of hydraulic stations and water pools in alternate freezing and thawing zone (in regime as per GOST 10060-87) the crack opening width depending on a number of cycles of alternate freezing a year shall be equal, in cm, not more than: 0.015 at a number of cycles less than 50; 0.010 ditto, 50 and more.

3.97. *. Compressive concrete of structures designed by category of requirements as per crack resistance 2a, when checked the possibility of loaded erecting crane operation on the bridge part under erection, permits to take: limiting values of normal tensile stresses in concrete - 1.15Rbt,ser; limiting values of crack opening designed width - 0.01 cm. De-tensioning in stressed reinforcement corresponding to losses a year should be taken into consideration in the design.

3.98. *. In members of structures designed by category of requirements as per crack resistance 2a, 2б, and 3б, in zones of concrete compressed in the stage of operation under dead and live loads of structures it shall not be allowed the origin of tensile stresses exceeding 0.8Rbt,ser in other stages.

CRACK FORMATION DESIGN 3.99. *. Crack resistance of bridge and culvert reinforced concrete structures is ensured by limitations of tensile and compressing stresses occurred in members and of concrete structures – by limitations of compressing stresses. The limit values of mentioned stresses are taken depending on the conditions that should be provided: a) cracks appearance (formation) in structure members is not permitted; b) appearance of cracks with opening limited by width is permitted (possible).

3.100. *. Formation of longitudinal cracks caused by normal compressing stresses in all structures and at all stages of their performance is not permitted. Originating from acting normal loads and impacts the normal compressing stresses σbx in member sections shall not exceed: rated resistance Rb,mc2 (taking into account items 3.48* and 3.97*) in concrete and reinforced concrete structures with untensioned reinforcement; rated resistance Rb,mc1(at a stage of fabrication and erection) and Rb,mc2 (at a stage of continuous operation). Main compressing stresses originating in concrete of prestressed beam webs shall not exceed the rated resistance Rb,mc2 of concrete in all cases.

SNiP 2.05.03-84 Page 86

3.101. . Formation of cracks normal to longitudinal member axis (perpendicular to normal tensile stresses action direction) is not permitted in the bridge structures designed by category of requirements as per crack resistance 2a, except a case when checking the erecting crane operation on the bridge. At this, random cross crack formation probability is not excluded. To fulfil these conditions the normal tensile stresses in compressing concrete shall not exceed the values indicated in Table 39* and item 3.97*.

3.102. . In structures designed by category of requirements as per crack resistance 2б, 3а, 3б, and 3а cross cracks formation can be assumed. At this, possibility of cross crack formation in structures designed by categories of requirements as per crack resistance 2б and 3a is limited by two indices given in Table 39*: maximum-permissible tensile stresses and designed width of possible cross crack opening. Besides that, in prestressed structures designed by category of requirements as per crack resistance 2б it should be ensured “the compressing” of cross cracks: limit values of minimum compressing stresses in concrete under compression in absence of live load the values shall be not less than the values indicated in Table 39*.

3.103. *. Main tensile stresses in concrete of prestressed beam webs shall be limited taking into consideration the ratio of main compressing stresses σmc to rated resistance of concrete Rb,mc2 against compressing, when considering the section as solid one. Limit values of main tensile stresses depending on the ratio of indicated values shall be taken not more than ones given in Table 40*.

Table 40*

σmc Limit values of main tensile stresses max σser , taken in bridges

Rb,mc2 Railway Motor road and city

≤ 0.52

≤ 0.52

0.68Rbt,ser, but not more than 1.75 MPa (18 kgf/cm2)

0.42Rbt, ser

0.85Rbt,ser, but not more than

2.15 MPa (22 kgf/cm2)

0.53Rbt,ser

Notes. 1. For intermediate values of ratio σmc2/Rbmc2 limit values max σser shall be determined by interpolation.

2. Preliminary value of main tensile stresses in the concrete of zones adjacent to glued joints in composite span structures shall be reduced to 10%. The mentioned zone length is taken as equal to a height of the joint each side thereof.

3.104. *. Main compressing and main tensile stresses indicated in items 3.100* and 3.103*, shall be determined by Equation

where σbx – normal stress in concrete lengthwise the longitudinal axis from external load and from forces in stressed reinforcement taking into consideration the losses; σby - normal stress in concrete in direction normal to longitudinal axis of member , from stressed stirrups, inclined reinforcement and support reaction stresses, at this, distribution of compressing forces from support reaction shall be specified at an angle 45°. τb - tangential stress in concrete of web (rib), determined by formula

)122(,4)(21)(

21 22

bbvbxbvbxmc

mt τσσσσσσ

+−±+=

SNiP 2.05.03-84 Page 87

τb = τq + τ1 ≤ mb6Rb,sh (123)

In Equation (123): τq - tangential stresses from shear force determined from external load and preliminary stress; τ1 - ditto, from torque; mb6 - coefficient specifying the action of cross compressing of concrete as per item 3.27; Rb,sh - rated resistance of concrete against shear when bent, taken as per Table 23*. When designed webs (ribs) of length-composite beams with concrete joints as per main stresses by Equation (122), tangential stresses on contact between cross compressed concrete of joint and blocks in the formula shall be limited to values equivalent in Equation (123), that right part together with the coefficient mb6 shall include the coefficient mb15 as well. When joints are not compressed it should be introduced the coefficient mb15 instead of coefficient mb6. Casting concrete section can be taken into consideration in design as per the second group limiting states if the design stipulates and structurally ensues transfer of shear force on contact of casting concrete with concrete of blocks and provided shearing stresses in concrete on contact don’t exceed 0.5Rb,sh as per Table 23*. The section of injecting grout in closed channels can be considered completely in the design. Normal and tangential stresses in members with height variable on the span length shall be determined taking into consideration the section variability.

CRACK OPENING DESIGN

3.105. Opening width of normal and inclined to a longitudinal axis cracks αcr in reinforced concrete members designed by categories of requirements against cracks 2б, 3а, 3б, and 3в shall be calculated as:

where σ - tensile stress equal to stress σs in the most tensile (end) bars for untensioned reinforcement; and equal to an stress increment ∆σp after suppress of stressing of concrete for stressed reinforcement. E - modulus of elasticity respectively for untensioned Es and stressed Ep reinforcement taken as per Table 34; - crack opening coefficient determined depending on radius of reinforcing (specify the tensile zone concrete influence, strains of reinforement, its shape and member behaviour conditions) and taken as per item 3.109*; ∆cr - limit value of designed width of crack opening; see data taken as per Table 39*.

3.106. *. When determined crack width by formula (124) with mix reinforcement the value σ/E taking into consideration the tensile stresses in untensioned reinforcement σs and increment of stresses in tensioned reinforcement ∆σp after suppress of prestressing of concrete up to zero is determined by formula:

where ψ1 - coefficient of crack opening for untensioned reinforcement according to item 3.109*; ψ2 - ditto, for stressed reinforcement according to item 3.109*. Equations (126) and (127) are excluded.

)124(,crcr E∆≤= ψ

σα

*)125(,

1

21

21

ψψ

ψσ

ψσ

σ+

∆+

= p

p

s EEE

SNiP 2.05.03-84 Page 88

3.107. *. Tensile stresses σs in transverse and longitudinal reinforcement of beam webs (ribs) can be determined by Equation:

where σbt - stress in prestressed beams without tensioned stirrups, taken equal to main tensile stress σml at a level of gravity centre of the section; in beams with untensioned reinforcement – equal to tangential stress τ at the same level; - coefficient of reinforcing the web with bars crossing the inclined section (between chords haunches) determined as a ratio of projection of these bars section area onto the normal to inclined section - to concrete area of inclined section. δ - coefficient specifying re-distribution of stresses in inclined crack formation zone and determined as:

where lf - length, cm, of supposed inclined crack at a section between chords haunches (in T-shape beams the beginning of inclined section is taken from the first row of tensile reinforcement towards the neutral axis); crack inclination shall be taken according to item 3.79*. Dwg No.10. Projection of forces in transverse reinforcement onto the normal to inclined section 1-normal; 2-stirrup; 3-inclined section; 4 - longitudinal reinforcement; 5 – tangent to bundle; 6 – haunch. 3.108. *. When determined normal cracks width in tensile zone of prestressed members all tensile reinforcement shall be taken into consideration. When determined crack width in prestressed piles it is permitted to specify all reinforcement of tensile zone. Increment of tensile tension ∆σ in stressed reinforcement according to item 3.105 originating after reducing under live load the precompressing stress in concrete to zero can be determined by

Equation: where σbt - tensile stress in concrete at a level of gravity centre of the concrete tensile zone area; µp - coefficient of reinforcing determined as a ratio of specified cross section area of longitudinal reinforcement to the area of all tensile zone of concrete (reinforcement not bonded with concrete is not specified when calculated µp). With mixed reinforcing the concrete stress σbt is determined at a level of gravity centre of that part of concrete tensile zone where tensile stresses don’t exceed 1.4σbt,ser . Untensioned reinforcement stresses in case of mix reinforcing can be determined by the formula

where σbts - stresses in concrete at a level of gravity centre of tensile zone area Abts part

)128(,µ

σδσ bt

s =

)129(,75.0/5.01

1≤

+=

µ

δfl

)130(,p

btsp µ

σσ =∆

,s

btss µ

σσ =

SNiP 2.05.03-84 Page 89

within the limits of that the stresses in concrete exceeds1.4 σbt,ser :

3.109. *. Crack opening coefficients ψ shall be taken depending on reinforcing radius Rr (cm), equal to: 0.35 Rr - for plain bar reinforcement, tendons of plain wire, and for locked steel wire ropes; 1.5 √Rr - for deformed bars, corrugated wire, tendons of this wire, strands of class K-7 and their tendons, steel wire ropes of spiral and twin stranded wire, as well as for any reinforcement in webs.

3.110. *. When calculated the normal crack width the radius of reinforcing shall be determined

as follows: where Ar - area of interacting zone for normal section accepted as limited with section outline and radius of interacting r = 6d; β - coefficient taking into consideration bonding capacity of reinforcing bars to concrete according to Table 41*; n - number of reinforcing bars with similar nominal diameter d; d - diameter of one bar (including cases of bar arrangements in groups). For non-rectangular sections with reinforcement uniformly distributed over the outline the interacting radius is taken as r = 3d. For tendons and wire ropes d corresponds to outline of reinforcing element, and r = 5d.

Table 41* Kind of reinforcing the structure Coefficient β

1. Single bars (plain and deformed), single corrugated wires or strands of class K-7

1.0

2. Vertical rows by two bars (continuous), groups of twin bars (gaps between bar groups)

0.85

3. Ditto, by three bars (gaps between bar groups), steel wire ropes of spiral and twin stranded wire, tendons from strands of class K-7

0.75

4. Tendons with number of wires up to 24 inclusively 0.65

5. Tendons with number of wire over 24 or locked steel wire ropes. 0.5

Radius of interacting r shall be measured from the first bar, nearest to a row neutral axis. If in the first row there installed less than a half of cross section area of bars relative to the area of bars in each of other rows, then r shall be measured from next to the last row with complete number of bars; in round sections r shall be measured from an axis of the most stressed bar to the side of neutral axis, and in case of bundled bars – from an axis of inner bar of the most stressed bundled bars. The interacting zone shall not spread beyond the neutral axis and it should be not high than a depth of section, and in centrally tensile members it is accepted equal to all area of section. In round sections the interacting zone area and radius of reinforcing shall be determined for the most stressed bar or bundled bars. Formula (132) is excluded. When designed inclined crack width the radius of reinforcing shall be determined from the Equation:

bts

ss A

A=µ

)131(,nd

AR rr βΣ

=

)132(,coscoscos

uu dndndn

ARαβαβαβ Σ+Σ+Σ

=

SNiP 2.05.03-84 Page 90

where Ar - interacting zone area for inclined section determined by formula Ar = lib; li - web inclined section length according to item 3.107*; b - web depth ; ni,nw,nl - number of inclined bars, stirrup branches and longitudinal bars within the limits of inclined section; di,dw,dl - diameters, respectively, of inclined bars (or tendons), stirrups and longitudinal bars crossing inclined section within the web; αi,αw,αl - angles between inclined bars (or bars) stirrups, longitudinal bars and the normal to inclined section according to dwg.10.

3.111. *. Resistance of members against cracks from local stresses, caused by applied concentrated forces of pre-stresses, and the web (beam) bending under local load can be provided by means of installation of additional reinforcement that takes up from concrete all tensile force from local actions in assumption of crack formation on the part under consideration. At this, calculated crack depth should not exceed the depth rated for category of requirements on crack resistance 3б or 3в ( refer to Table 39*). For parts where mentioned stresses don't exceed 0.4Rbt,ser, reinforcement can be carried out structurally. When designed the concrete for local compression under anchor a force transmitted by the latter shall be taken equal to: 100 % of reinforcement force when post-tensioning; 30% of reinforcement force when pretentioning the tendon with inner anchor.

DETERMINATION OF DEFLECTIONS AND DEFLECTION ANGLES 3.112. Deflections, deflection angles and lengthwise shifts are calculated by structural mechanics formulae depending on members curvature 1/p as well as relative lengthwise shifts, that are determined on the base of a hypothesis of flat sections for overall (elastic and inelastic) deformations. Deflection ƒ or deflection angle α, stipulated by the member flexure strains shall be determined as follows:

where M(x) - when determined a deflection f it is a function of bending moment of unit force, applied in direction of the unknown deflection f ; when determined a deflection angle α it is a function of bending moment from the unit moment, applied in direction of the unknown deflection angle. 1/p(x) - member curvature in the same section caused by load applied for determination of a deflection or deflection angle (the sign is taken as per the sign of bending moment in the given section). In Equation (134) summation extends all over the parts (lengthwise the deck) different by laws of variation of values M(x) and 1/p(x). Deflections (deflection angles) can be calculated by numerical methods using the expression

where M(x) and 1/p(x) are mean values of moment and curvature on separate parts of length ∆x, where variation of mentioned parameters has a smooth character.

3.113. *. Curvature of prestressed members, where chords are referred to category of requirements as per crack resistance 2a, 2б and 3б, can be determined as for the solid section by Equation

)134(,)(1)()(0

dxxp

xMfl

∫∑=α

)135(,)(1)()( xxp

xMf ∆∑=α

)136(,1∗∗∗ ++=

MMMp

vgp

SNiP 2.05.03-84 Page 91

where Mp, Mg, Mv - moments in section under consideration created by a force in stressed reinforcement, by dead and live load, respectively; Bp,* Bg* - rigidities of section under long action of a force in stressed reinforcement and dead load, respectively; B - rigidity of solid section under short action of loads. Values of mentioned rigidities can be determined as per the Obligatory Appendix 13*. The Equation (136) right part can be determined by other methods proved in established order. Moments from pre-stress shall be calculated based on reinforcement stresses corresponding to stages of structure behavior; at a stage of compressing – minus the first losses; at consequent stages including the performance stage - minus the second losses also according to Obligatory Appendix 11*. Bending moment values Mg during cantilevering shall be determined taking into account weight of blocks under erection and other possible constructional loads. When determined rigidities Bp* and Bg* the prestress force effect and duration of load action are taken into account

3.114. *. Curvature of untensioned reinforcement members, where chords are referred to category of requirements as per crack resistance 3в can be determined as follows:

where Bg* - rigidity of section under dead load action with allowance for crack formation and concrete creep; B - rigidity of solid section under live load short action with allowance for crack formation. In calculating the members curvature it is permitted to consider that all dead load acts in concrete of one and the same age, corresponding to application of the most part of this load. Stressed reinforcement members curvature on the parts with cracks (more than 0.015 cm wide) in tensile zone can be determined by the instructions of SNiP 2.03.01-84.

3.115. *. When designed the deflection of beams with untensioned reinforcement (if crack in concrete is not more than 0.015 cm wide) by formula of resistances of elastic materials as well as when designed the shift of piers, posts, encased piles (including concrete piles) not depending on the section crack measured width, the rigidity can be determined as follows: B= 0.8 EbJb , here Jb is inertia moment of concrete section. Shifts of mass concrete and reinforced concrete members (piers) under live and dead loads can be computed including rigidities determined by complete sections of members not taking into consideration creep and shrinkage of concrete.

STRUCTURAL REQUIREMENTS 3.116. . In designing the concrete and reinforced concrete structures to provide conditions of their fabrication, required durability and combined behavior of reinforcement and concrete it is necessary to follow the structural requirements described in the present Section.

MINIMUM DIMENSIONS OF MEMBERS SECTION 3.117. Depth of webs, slabs, diaphragms and ribs in reinforced concrete members shall be taken not less than as indicated in Table 42.

Table 42 Members and their parts Minimum depth, in cm, for structures of

bridges and culverts railway highway

)137(,1∗∗

+=B

M

B

M

py

g

g

SNiP 2.05.03-84 Page 92

1. Vertical or inclined webs of beams: a) ribbed

without tendons in webs with tendons in webs

12* 15

10* 12*

b) box girder without tendons in webs

with tendons in webs

15 18

12* 15

2. Slabs: a) of ballast pocket: between webs (ribs) at ends of cantilevers b) of bridge floor part:

between webs (ribs) without tendons in slab with tendons in slab at end of cantilevers c) lower slabs in box girder:

without tendons in slab with tendons in slab

d) sidewalks: cast-in-place ( non-removable) precast (removable)

15 10 - - - -

15 16

8 6

- - -

12 15 8

12 15

8 6

3. Hollow blocks of slab deck **: a) with reinforcement from bars, single strand

of class K-7 and tendons of parallel high strength wires: webs and upper slabs lower slabs

b) wire stressed precast concrete: webs and upper slabs lower slabs

10 12 - -

8 10

6 7

4. Diaphragms and web stiffeners of decks 10 10 5. Webs of links of pipes under fills 10 10*** 6. Walls of box and round section blocks of hollow

and precast-monolithic piers: in zone of variable water level out of zone of variable water level

30 15

15 15

7. Webs of reinforced concrete hollow piles and encased piles of outer diameter, m

0.4 from 0.6 to 0.8 from 1.0 to 3.0

8 10 12

8 10 12

* When applied two reinforcing meshes the minimum depth of walls is taken equal to 15 cm. ** In hollow blocks with curvature outline of upper and lower parts of space between walls an average reduced value calculated on the space width can be taken as a minimum depth of a slab. *** For pipes in dia 0.5 and 0.75 it is permitted to take wall depth equal to 8 cm

SNiP 2.05.03-84 Page 93

Table 43

Kind of reinforcement Reinforcement minimum diameter in mm

1. Designed longitudinal reinforcement in members of bridges (except members mentioned below) and rectangular culverts

12

2. Designed reinforcement for floors (including sidewalks) of highway bridges

10

3. Designed and constructional reinforcement in links of round pipes; constructional longitudinal and transverse reinforcement in members of bridges (except slabs); stirrups in beam webs and widening of chords all over the length.

8

4. Wire reinforcement, class Bp for slope fixing slabs and stirrups of pile reinforcement (see item 3.35*), 5 mm in dia.

10

5. Constructional (distributing) reinforcement in slabs; stirrups of piles and encased piles; stirrups in hollow slabs.

6

MINIMUM DIAMETERS OF UNTENSIONED REINFORCEMENT 3.118. *. Untensioned reinforcement minimum diameters shall be specified as per Table 43*.

Distributing reinforcement in slabs and stirrups in piles when reinforcement is longitudinal with diameter 28 mm and more shall have a diameter not less than a quarter of diameter of longitudinal bars.

COVER OF CONCRETE OVER REINFORCEMENT 3.119. *. Thickness of concrete cover from its outer surface to reinforcing member or channel shall be not less than one indicated in Table 44.

3.120. . The concrete cover thickness at the ends of prestressed members on the length of force transmission (according to item 3.11) shall be not less than two diameters of reinforcement. When applied stressed bar reinforcing steel, class A-V, Aт-V and Ат-VI, it is necessary to install additionally on the length of force transmission (see item 3.11) the meshes, spirals with diameter exceeding by 4 cm the bar diameter or to install locked stirrups with a pitch not more than 5 cm.

Table 44* Kind of reinforcement and its location Minimum thickness of

cover of concrete, cm 1. Untensioned principal reinforcement:

Upper reinforcement in slabs of floor of highway and city bridges, In ribbed and slab decks as well as in slabs 30 cm high and more in slabs, less than 30 cm high in pipe links and hollow encased piles in outer blocks of precast piers near outer surfaces of monolithic piers:

a) in ice-guard part of pier b) on other parts of pier c) in piles, manholes and blocks of precast

foundations in support slabs of monolithic reinforced concrete

foundations: a) in availability of blinding concrete b) without blinding concrete

5

3

2 2*

7 5 3

4 7

2. Untensioned stirrups

SNiP 2.05.03-84 Page 94

in webs (stiffeners) of beams in legs of piers:

a) out of the zone of variable water level b) in zone of variable water level

2

2 3

3. Constructional (non-designed ) longitudinal reinforcement in webs (stiffeners) of beams and in slabs

1.5

4. Untensioned reinforcement installed in cast concreting the stressed reinforcement.

3

5. Stressed reinforcement in tensile zone of section: a) in form of tendons of high-strength wires and

tendons of class K-7 strands b) from reinforcing steel, class A-IV, Aт-IV class A-V, Aт –V, Aт –VI c) from steel wire ropes (spiral, twin and locked),

in dia d > 40 mm with anchors at the end

4**

4 5 d

6. Stressed reinforcement of all kinds in slab of bridge floor part, waterproof protected

3

7. Stressed stirrups in webs (stiffeners) 3 8. Stressed reinforcement in wire stressed precast

concrete from the side of: tensile face lateral faces __________________________

3***

2

*For pipes in dia 3 m and more the cover of concrete to reinforcement is 3 cm; **For stressed reinforcement placed in closed ducts the cover of concrete over reinforcement is determined relative to the duct surface. For ducts in dia 11 cm the cover of concrete shall be taken equal to 5 cm. When diameter is more than 11 cm, the concrete cover to reinforcement shall be checked by design for force actions and pressure of mortar during injection. ***For members with thickness less than 20 cm the concrete cover to reinforcement can be reduced to 2 cm.

MINIMUM DISTANCES BETWEEN REINFORCING MEMBERS 3.121. . Clear distance between separate reinforcing elements as well as between walls of ducts shall provide the required pouring with concrete mixture of the whole structure. Besides, in presstressed structures these distances shall be specified with allowance of particular feature of stressed reinforcement-to-concrete force transmission, placing of anchors, dimensions of applied tension equipment.

3.122. *. Clear distance between separate longitudinal principal bars of untensioned reinforcement and tendons of pretensioning reinforcement shall be specified as follows. if bars occupy horizontal or inclined position when placing the concrete, not less than: 4 cm with one row arrangement; 5 cm with two row arrangement; 6 cm with three row arrangement and more; if bars occupy vertical position when placing the concrete it shall be 5 cm. In constraint conditions it is possible to arrange untensioned reinforcing bars in groups (less gaps between bars) of two or three bars. Clear distance by width shall be specified not less than: 5cm with two bars in a group; 6cm with three bars in a group;

SNiP 2.05.03-84 Page 95

3.123. *. When specified clear distance between reinforcing elements in prestressed structures it should be observed the requirements given in Table 45*. In mixed reinforcing the minimum distance between the untensioned reinforcing bar and tendon or web of closed duct shall be taken not less than 3 cm.

Table 45* Minimum distance

Specified clear distances By absolute value

Depending on dia d of reinforcing element or dia dc of duct

In structures with pretensioning reinforcement Between tendons of parallel high-strength wires 6 d 2. Between tendons and outer surfaces of their inside anchors

4 -

3, Between outer surfaces of inside anchors of tendons

3 -

4. Between separate strands of class K-7 with their arrangement: in one row in two rows and more

4 5

- -

Distance from inside anchor end to the end of concrete

5

In structures with post-tensioning reinforcement 6. Between webs of closed round ducts of dia, cm: 9 and less above 9 to 11

6 8

dc-1

- above 11

as per design

7. Between tendons of parallel high-strength wires, tendons of strands of class K-7, and also steel ropes (spiral, twin stranded, and locked) when placed them into open ducts as follows:

in one row in two rows

3 4

- -

9. Between walls of ducts with single bars tensioned by electrothermal method:

in closed ducts in open ducts

10 13

- -

ANCHORAGE OF UNTENSIONED REINFORCEMENT 3.124. *. Deformed reinforcing bars as well as plain bars in welded meshes and frames can be applied without hooked ends. Tensile principal bars of plain shape as well as plain principal bars in tied meshes and frames shall be semiround-bent at the ends, with inner diameter not less than 2.5 of the bar diameter and with a length of straight part after bending not less than 3 diameters of the bar.

3.125. *. In deflected simply supported beams and in slab structures 30 cm deep and more the ends of tensile bars, when they break as per the moment curve, are required, as a rule to be anchored in compressed zone of concrete determined in computations of crack resistance. The plain bars brought into compressed zone by means of bending shall be ended with straight hooks having after bending a straight length not less than 3 diameters of the bar.

SNiP 2.05.03-84 Page 96

In highway and city bridges in case of deformed bars and with weld joints the bars can be embedded into concrete tensile zone of deflected and eccentrically compressed members to a length not less than 30 diameters of bars behind the place of their theoretical break. Besides that, in span structures the bar ends to be end-anchored shall be welded to adjacent bars at a length not less than 4 d. with a throat thickness not less than 4 mm

3.126. . The beginning of bend-ups of longitudinal tensile bars of deformed reinforcement in deflected members or a break of such bars in eccentrically compressed members shall be placed behind the section where the bars are specified with complete rated resistance. The length of bringing the bar behind the section (embedded length ls) for reinforcing steel, class A-II and Ac-II shall be not less than: 22 d - for concrete of class B30 and more; 25 d - for concrete of class B20-B27.5 (d – diameter of a bar). For reinforcing steel, class A-III, the embedding length ls shall be increased to 5 d, respectively. In case of tendons d is determined as a reference bar diameter with area equal to total area of bars formed a tendon.

3.127. *. In simple supported beams and at the ends of continuous beams the tensile bars of longitudinal reinforcement brought behind the bearing part axis shall have straight lengths not less than 8 diameters of the bar. Besides that, the first bars connected to lateral surfaces of the beam shall be bent at the end face under an angle 90° and continue up to a half of the beam depth. The distance from the beam end face to the bearing axis is required to provide equal to not less than 30 cm and not less than 15 cm to the bearing plate edge.

3.128. . Excessive bends of tensile bars of longitudinal reinforcement by outline of the reentering angles creating when changed the member surface are not allowed. Longitudinal reinforcement bars located along the planes forming the angle of change shall be continued behind the point of their crossing to a length not less than 22 diameters of bars.

STRESSED BAR ANCHORAGE 3.129. *. When structure applies pretension reinforcement of deformed bars of diameter up to 35 mm, the anchorage of bars are not required. In members with reinforcement designed for durability the all bars (except above mentioned) should have inner or outside (end) anchors. In members with pretension reinforcement not designed for durability the separate strands of class K-7 and separate high-strength corrugated wire can be applied without anchors (inner and outside). The strength of anchorage applied in structures with tensioning to concrete shall be not less than the strength of reinforcing elements fixed with anchors.

3.130. . Deflected members shall avoid the placing of reinforcement anchors in zones of concrete where main tensile and compressing stresses are above 90% of limiting values established for these stresses.

3.131. *. Outside (end) anchors on the beam end surface shall be placed uniformly as much as possible. At this, care shall be taken to mount on the end the solid steel plates overlapping the concrete of anchor place zone. The plate edges shall be end-anchored in concrete. The end plate thickness shall be specified by the design depending on tension forces of reinforcing elements under tension and it shall be taken, mm, not less than: 10 - with tension force 590 kN (60 tf) 20 - with tension force 1180 kN (120 tf) 40 - with tension force 2750 kN (280 tf) With forces other than those indicated ones it shall be taken a plate thickness corresponding to the nearest large value.

SNiP 2.05.03-84 Page 97

3.132. . In members with post-tensioning the external anchors zone of concreting shall be reinforced with transverse meshes of deformed bars, diameter not less than 10 mm with cells not more than 10x10 cm and interval between meshes 10 cm.

LONGITUDINAL REINFORCING OF MEMBERS 3.133. *. In welded reinforcing frames the reinforcement is arranged by groups, not more than three bars in each group. Bars in group are tied together with one-sided connecting welds. The length of connecting welds between bars shall be not less than 4 diameters and their throat, not more than 4 mm. Gaps between the bar groups are formed by means of installing the short longitudinal bars of diameter not less than 25 mm. Short bars are installed in front of the bend-ups; not more than every 2.5 m by length in staggered order relative to each other. They are welded to principal reinforcement with one-sided connecting welds of throat not more than 4 mm and of length not less than 2 diameters of principal bars. Connecting welds between bars in group are positioned in staggered order relative to short bars and adjacent connecting welds in such a way that clearance between welds is not less than 40 cm in case if adjacent welds are applied to the total longitudinal bar, and 10 cm if connecting welds are referred to different longitudinal bars of the frame. Besides that, it should be kept that any transverse section of bar group has crossed not more than one weld. With relevant grounds the vertical bars of welded meshes in walls are permitted to weld by resistance spot welding to reinforcement and to longitudinal short bars positioned between the bar groups. Stirrups are prohibited to weld to main reinforcement by electric arc welding. For main principal reinforcement of frames it is recommended to apply the reinforcement of class Ac-II 10ГТ. Welds that fix to principal reinforcement are instructed in item.3.160*.

3.134. *. In simple-supported beams and slabs at least one third of designed reinforcement installed in the middle of span shall be brought to the support. At this, in beams it shall be brought to the support at least two bars and in slabs at least three bars for 1 m of slab width. The slab distributing reinforcement shall be installed with a pitch not exceeding 25cm. At mixed reinforcing the untensioned reinforcing bars can be installed by pairs, at this, these bars protective coat thickness shall corresponds to item 3.119*, and distance between bars and tendons - to item 3.122* and 3.123*.

3.135. In simple supported beams and cross bars of multi-span frame structures a part of upper and lower principal reinforcement should be continuous by length or have joints overlapping the break of reinforcing. Number of continuous reinforcing elements should be: a) at least 20% of lower and 15% of upper principal reinforcement in structures with untensioned reinforcing bars; b) at least 10% of lower and 5% of upper principal reinforcement in structures with tensioned reinforcing bars, but not less than two lower and two upper reinforcing elements.

3.136. Pitch (distance between axes) of principal reinforcement of a slab in the middle of the span and above its supports should not exceed, in cm: 15 – in slabs of ballast pocket of railway bridges; 20 – in slabs of roadway of highway bridges.

TRANSVERSE REINFORCING OF MEMBERS 3.137. To take shear forces the untensioned beam webs shall be reinforced with inclined and vertical bars (stirrups) and the latter shall be united with longitudinal reinforcement of webs forming frames and meshes.

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3.138. In untensioned beams the inclined bars installed according to design shall be placed symmetrically about the longitudinal axis of deflected member. Bars, as a rule, about the longitudinal axis of the member should have an angle of inclination close to 45°C (not more than 30°C and not less than 30°C). At this, on the beam part where the design requires to place inclined bars, any section perpendicular to longitudinal axis of the beam should cross at least one bar of inclined reinforcement.

3.139. *. Required by beam design additional inclined bars shall be fixed to the principal longitudinal reinforcement. If reinforcing bars are made of steel of classes A-I, A-II, Ac-II, and A-III, then additional inclined bars can be fixed by welds.

3.140. Inclined reinforcement bars in beams shall be bent by arc of a circle with radius not less than 10 diameters of bars. Longitudinal reinforcement near end faces of the beam (behind an axis of bearing part) can be bent by arc of a circle with radius not less than three diameters of bars.

3.141. Longitudinal reinforcement in webs of untensioned beams shall be installed as follows: within one third of web depth beginning from tensile beam face – with a pitch not more than 12 diameters of bars applied (d = 8 - 12 mm); within the rest part of web depth - with a pitch not more than 20 diameters of bars (d = 8 – 10 mm).

3.142. Stressed reinforcing members, having parts which direction don’t coincide with direction of beam longitudinal axis shall be placed, as a rule, symmetrically about the longitudinal axis of the beam.

3.143. *. Stirrups in beams are installed as per design, including design on section between stirrups. In webs up to 50 cm deep, within near-support parts of length equal to 1/4 of deck counting from an axis of support a stirrup pitch is taken not more than 15 cm. On the beam middle part of length equal to 1/2 of deck a stirrup pitch is taken not more than 20 cm. With web depth more than 50 cm a stirrup maximum pitch in the middle of the deck can be increased by 5 cm. Twin stirrups made of reinforcement of one class and diameter can be applied.

3.144. Stirrups in simply supported slab decks shall be installed with a pitch not exceeding, in cm: 15 - on parts adjacent to bearing members and having a length equal to ¼ of deck; 25 – on the middle part having a length equal to ½ of deck. In solid slabs of the ballast pocket of railway bridges and floor of highway bridges of 30 cm high and less the stirrups in absence of compressed designed reinforcement can be not installed. Note. In slab decks of highway and city bridges the transverse reinforcement can not be installed in slabs of 40 cm deep if tangential stresses in concrete don’t exceed 0.25Rb,sh (where Rb,sh – rated resistance of concrete against shear during bending according to Table 23*).

3.145. Stirrups in chords of untensioned beams should cover the chord width not more than 50 cm and unite not more than five tensile and not more than three compressed bars of longitudinal reinforcement installed in the first horizontal rows.

3.146. Widening part of beam chords shall be reinforced with locked stirrups made of deformed bars; stirrup branches should cover the whole outside contour of chords.

3.147. The maximum pitch of locked stirrups or transverse bars in welded meshes of compressed chords of stressed beams shall be specified not more than 15 cm in railway and 20 cm in highway bridges. Stirrup pitch in compressed chords should not exceed a pitch of stirrups in beam webs.

3.148. Stirrups in members rated for torque as well as for twisting together with bend, compression or tension shall be locked with by-pass of ends:

for 30 diameters, with stirrups made of plain reinforcing steel;

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for 20 diameters, ditto, made of corrugated reinforcing steel.

3.149. In zone of placing the anchors of stressed reinforcing members under base plates (see i.3.131*) it should be installed additional transverse (lateral) reinforcement by design for local stresses.

Additional reinforcement is made of deformed bars with a pitch between them in cm not mote than:

10 - in meshes; 5 - in spiral.

3.150. Longitudinal main reinforcement and stirrups in compressed members of structures shall be united into frames. A stirrup pitch depending on longitudinal reinforcing bars diameter d shall be specified not more than: 15 d – in case of welded frames; 12 d – in case of tied frames. In all cases a stirrup pitch shall be specified, in cm, not more than: 40 - with percentage of longitudinal reinforcement less than 3% ; 30 - with percentage of longitudinal reinforcement 3% and more. With significant percentage of longitudinal reinforcement instead of separate stirrups it is recommended to accept continuous transverse reinforcement by twisted bars repeating the outline of the member cross-section.

3.151. *.Square-shape or rectangular cross-section support compressed member stirrups structure shall provide that longitudinal bars would be installed in place of stirrup bending, and stirrup branches installed lengthwise the member face would hold not more than four bars of longitudinal reinforcement and would have a length not more than 40 cm. The mentioned instructions are for supports with faces not more than 80 cm. In case of exceeding this size, the support longitudinal main bars installed on opposite faces can not be integrated between each other by stirrups crossing the support section, and the latter can be changed for perimeter-mounted small chains of structural П-shape stirrups, each 40 cm long, with lateral anchoring branches not less than 20 cm long, installed in perpendicular to the main longitudinal stirrup branch in direction into the section of concrete. Short branch ends ended with semi-round hooks are fixed to vertical erection bars installed all over the support height. Stirrups overlap each other in place of bending. Stirrups chains covering the supports by perimeter are placed on height every 40 cm. For stirrups and erection vertical bars it shall be applied reinforcement of diameter not less than 10 mm. To improve the stability of support compressed main bars, besides stirrup small chains, it is required to install erection braces connecting the longitudinal vertical bars on transverse faces of the support. Braces should consist of three bars in diameter not less than 16 mm and be installed in plan and on height at least every 1.6 m. To avoid difficulties in placing the concrete because of bars crossing the section, the braces on each stage can be installed and fixed in succession directly before placing each layer of concrete.

3.152. On end parts of compressed members transferring the load through the end faces without free lengths of longitudinal reinforcing bars it shall be installed transverse welded meshes in a number not less than four (in piles it should be five meshes). Length of end parts reinforced with meshes shall be specified not less than 20 diameters of longitudinal reinforcing bars, and distance between meshes, not more than 10 cm.

3.153. In indirect reinforcing of compressed members with untensioned reinforcement (see i.3.72*) the applied welded transverse meshes and spirals shall be made of reinforcing steel of class A-II, Ac-II and A-III (diameter not more than 14 mm). Bars of transverse meshes and spiral turns should cover all main longitudinal reinforcement of the member. Transverse mesh cell size shall be specified not less than 5.5 cm and not more than ¼ of the member section smaller side or 10 cm. Transverse mesh pitch lengthwise the member shall be specified not less than 6 cm and not more than 1/3 of the member section smaller side or 10cm.

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Spirals should have diameter of winding not less than 20 cm. Spiral turns pitch should be specified not less than 4 cm and not more than 1/5 of the member section diameter or 10 cm.

3.154. In links of round pipes and cylinder enclosures when reinforced with double meshes the main reinforcing bars shall be tied in radial direction by connection fixing bars or be integrated to the frames.

WELD JOINTS OF REINFORCEMENT 3.155. *. Weld joints of the reinforcement shall be in conformity with the requirements of GOST 14098-91 and GOST 10922-90. In designing it shall be indicated a responsibility category for applied joints and the corresponding category of requirements to quality control of weld joints. Weld joints, which bearing capacity is determined by the first limiting state are referred to category I, by the second limiting state - to category II, and all other cases – to category III of responsibility, and respectively, to category III of joint quality. The inspection volume for each responsibility category is determined following the instructions of SNiP III-18-75.

3.156. *. Hot-rolled rod reinforcing steel of classes and quality indicated in Table 29*, as a rule, shall be connected by means of resistance butt welding. Resistance butt welding can be applied for bars of diameter 10 mm and less only under factory conditions in availability of special equipment. It is allowed to use the resistance welding to butt the reinforcing bars with a ratio of butted bar areas not more than 1.15. In reinforcing elements rated for endurance the stress raisers originating during welding in butt zone is required, as a rule, to be eliminated by means of proper mechanical longitudinal dressing. Other effective structural decisions of weld joints are allowed to be applied provided that confined limit of endurance of these joints will be not less than the standard endurance limit of reinforcing bars under welding.

3.157. *. Welded meshes including those as per GOST 23279-85, as well as frames shall be designed, as a rule, with applying the resistance spot welding in crossings of bars. When using reinforcing steel of classes A-I, A-II, Ac-II and A-III for meshes and frames that according to instructions of Table 29* shall be presented as tied models, the weld joints for main reinforcement can be permitted only in places where stresses in bars don’t exceed 50% of installed rated resistance

3.158.

3.159. *. A number of butts in one rated section of element (within the length equal to 15 diameters of butted bars) should not exceed 25 % of total number of main reinforcement in tensile zone of section in members which reinforcement is rated for endurance, and 40% in members which reinforcement is not rated for endurance. Reinforcement weld butts can be executed not in the staggered order in erection butt joints of precast members (less reducing the rated resistance of reinforcement), as well as in parts of structure where reinforcement is used not more than for 50%.

3.160. *. For butts of rod hot-rolled reinforcement of steel class A-I, A-II, Ac-II and A-III in erection of structures the welding in bath can be used on elongated steel straps (backs), length not less than 5 diameters of bars as well as it can be used the butts with double offset straps welded with one-side or two-side welds of total length not less than 10 diameters of butted bars. Bath welding can be applied when bar diameter is not less than 20 mm. For compressed bar butts not rated for endurance it is possible to apply bath welding on short steel strips (backs) in conformity with GOST 14098-91. Length of one-side weld joints fixing the inclined reinforcing bars should be not less than 12 diameters with throat thickness not less than 0.25 d and not less than 4 mm; two-side welds can be two times less.

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3.161. *.Erection free lengths in butt joints shall ensure conditions for qualitative execution of bath welding on elongated straps with smooth leading out of longitudinal welds to butted bars. In tied reinforcing frames of highway and city bridge structures to fix the reinforcement in designed position during installation, transportation and placing the concrete it is allowed in crossings of main reinforcing bars with constructional bars to arrange additional weld joints observing the following conditions: the welding can be applied in places where strength of used main reinforcement is not more than 50 %, as well as where reinforcement acts only to compress.

LAP BUTT JOINTS OF UNTENSIONED REINFORCEMENT (WITHOUT WELDING) 3.162. . In eccentrically compressed and eccentrically tensile members the bars of corrugated steel of diameter up to 36 mm and plain bars with semi-round hooks can be lap-butted. In bending and centrally tensile members the lap butts of tensile reinforcing bars are not allowed.

3.163. *. In lap butts the length of lap (bypass) ls of bars of reinforcing steel, class A-II and Ac-II shall be taken not less than: 30 d - for grade of concrete B20-B27.5; 25 d - for grade of concrete B30 and higher, where d is a diameter of bars under butting. For bars of reinforcing steel class A-II the length of lap ls shall be increased by 4 d, respectively. For bars of reinforcing steel, class A-1 the length of lap ls (between inner surfaces of semi-rounded hooks) shall be specified the same as for bars of steel, class A-III. For butts located in compressed zone of the section the length of lap ls can be taken 5 d less than installed above. Separate welded and tied meshes shall be lap-butted to a length not less than 30 diameters of mesh longitudinal bars and not less than 25 cm.

3.164. *. With lap arrangement of butts of main reinforcing bars in tensile zone of section, where bar stresses exceed 75% of rated resistance, the butt zone requires to install the spiral reinforcement. If spiral reinforcement are not required (bar stresses are less than 75% of rated resistance) then distance between stirrups in place of lapped butting the main tensile reinforcing bars shall be specified not more than 6 cm, and in bored piers – 12 cm. Lapped butts of reinforcing bars, as a rule, shall be arranged in staggered order. At this, the sectional area of main bars butted on length of required lapping shall be not more than 50% of total sectional area of tensile reinforcement for deformed bars and not more than 25% for plain bars.

BUTT JOINTS OF PRECAST STRUCTURE MEMBERS 3.165. *. In precast structures the applied butt joints, as a rule, are as follows: concrete-filled, wide (uncompressed), with a distance between end faces of united members 10 cm and more, with free lengths out of members of main reinforcing bars or steel embedded pieces; concrete-filled, narrow (compressed), not more than 3 cm wide, without bar free lengths, with pouring cement or polymer-cement mortar to butt clearance; glued tight (compressed), with glue interlayer not more than 0.3 cm thick on epoxy resin base, or other long-life (experienced) polymer compositions. In justified cases in prestressed span structures of highway bridges it can be applied concrete-filled wide compressed butt joints less free lengths, with thickness up to 10 cm, but not more than a half of thickness of each of connected parts. Application of dry butts (without filling the glue compound, cement or polymer mortar between blocks) in span structures is not allowed.

3.166. . Block end faces of length- (height) composite span structures shall be reinforced with additional transverse meshes made of bars not less than 6 mm in diameter for case when butt joints are applied without reinforcement free lengths. When arranged tooth-shape butt joint or butt joint with shoulders the designed reinforcement of a tooth or shoulder should have the diameter not less than 10 mm.

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3.167. . In lengh- (height) composite structures with glued tight butt joints it should be installed, as a rule, spacers to ensure exact coincidence of surfaces to be butted.

3.168. *. Highway, city and combined bridges beam upper slabs not be subjected to direct action of railway moving load can use the concrete-filled butts with projections from the slabs of deformed bars with straight hooks all over the depth of a slab and with mutual bypassing the reinforcement lapped to a length not less than 15 diameters of bars and not less than 25 cm , as well as it can use semi-round loops lapped with mentioned bypassing length of loops each by each. Besides this, it is possible to use semi-round loops with the same length of their embedding but with straight insert of reinforcing bars between loops with a length equal to not less than the loop diameter. Semi-round loop diameter shall be taken not less than 10 diameters of reinforcement.

ADDITIONAL INSTRUCTIONS TO DESIGNING THE PRESTRESSED REINFORCED CONCRETE MEMBERS

3.169. . Stressed reinforcement in structures with tension to concrete shall be installed, as a rule, in closed ducts formed preferably by removable duct-formers from polymer materials. When ducts are formed by non-removable duct-formers it is recommended to apply non-galvanizing flexible steel sleeves and corrugated pipes. At this, the duct fill material shall not increase its volume in freezing and the protective concrete cover should exceed by 1 cm the value given in Table 44*. Non-removable duct-formers from continuous steel or polymer pipes can be used only on short sections in butts between precast blocks of length-composite structures and in place of bending and anchorage of the stresses reinforcement.

3.170. . To ensure bonding of cast-in-situ concrete in open ducts to concrete of prestressed member it should be provided as follows: reinforcement free lengths from concrete body of prestressed members or stirrup ends with spacing not more than 10 cm; coating of clean concrete surface attached to cast-in-situ concrete and stressed reinforcement with cement colloid or polymer-cement adhesive; application of water-cement ratio not more than 0.4 for in-situ casting concrete; coating of in-situ casting concrete outer surface with anti-shrinkage steam-isolation compound.

EMBEDDED ITEMS 3.171. * Embedded items from separate plates or shape profiles with T- or lap-welded anchor bars of reinforcing steel, class A-II, Ac-II and A-II, not more than 25 mm in diameter shall be designed in conformity with requirements of GOST 19292-85. Joints shall be welded in conformity with requirements of GOST 14098-91 and GOST 10922-90.

3.172. *. Embedded items shall not cut the concrete. Embedded to concrete, tensile anchored bars length shall be specified in dependence on concrete stressed state in direction perpendicular to bars to be anchored. If constantly acting loads (with load coefficient equal to 1) in anchor bar zone cause compressing stresses σbc, the most values of which respond to the condition

then the bar embedding length should be not less than: 12 d (d is bar diameter) with deformed reinforcing bars; 20 d, but not less than 25 cm with round reinforcing bars. If stresses in concrete σbc in embedding zone don’t correspond to the given above condition or nature of stresses is not determined, then the embedding length of tensile reinforcing bars shall be taken not less than: 25 d with reinforcing steel of class A-II and Ac-II; 30 d with reinforcing steel of class A-III.

25.075.0 >≥b

bc

Rσ

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The embedding length of tensile anchor bars can be reduced by means of welded flat steel members at the bar ends or by means of heads put on the bar ends by hot method. In so doing, the head diameter shall be not less than: 2 d with reinforcing steel, class A-II and Ac-II; 3 d with reinforcing steel, class A-III. In these cases the anchored bar embedding length is determined by calculation for chipping and compression of concrete and is specified not less than 10 d.

3.173. *. Ratio of flat steel member thickness δ of embedded part to diameter d of this part anchor bar (δ/d) shall be taken equal to:

a) automatic T-welding under flux, not less than: 0.55 – 0.65 for reinforcement, class A-II; 0.65 –0.75 for reinforcement, class A-III; b) manual T-welding under flux not less than 0.75 for reinforcement of all classes; c) manual welding to countersinking hole, not less than : 0.65 for reinforcement, class A-II; 0.75 for reinforcement, class A-III; d) arc welding, with side lap welds, not less than 0.3 for reinforcement of all classes.

DESIGNING OF PIERS 3.174. Railway bridge pier members located in zones of possible freezing of water (flowing water or that is available in soil) shall have the solid section. In highway and city bridges piers it can be applied in mentioned zones the reinforced concrete members in a form of hollow tubular pile providing measures (for ex. drain holes) against cracks formed in tubular walls due to force action of freezing water and ice inside the cavity of tubular piles.

3.175. Within ice drift level the pier body shall be formed taking into account the direction of ice drift action. The pier face to face connection shall be carried out by cylindrical surface with radius 0.75 m. With proper study this diameter can be reduced to 0.3 m.

3.176. On rivers located in regions with mean month ambient air temperature of the most cold month –20° C and more, the bridge intermediate piers (including reinforced concrete) can be carried out of concrete less special protection of surface. When designed the bridge piers in bed of the river with intensive river sediments transport (volume of suspended sediments more than 1 kgf per 1 m3 of flow and flow speed more than 2.5 m/s) the piers with legs from post-piles or tubular piles should be specially protected (steel banding shell, application of wear-resistant concrete for piers erection, etc.) in zones of sediments transport. Mass piers can be applied with its surfaces not additionally protected. Surfaces of intermediate concrete, reinforced concrete piers of bridges located in regions with mean month ambient air temperature of the most cold month below –20° C, and also, as a rule, the piers in rivers with breakup at negative mean daily ambient air temperature shall be covered with facing blocks within zone of ice drift variable level. At this, the thickness as well as the height of facing blocks should be not less than 40 cm. Facing blocks can be reinforced if it is required as per conditions of their transportation and anchorage against break action of ice. The mortar-filled vertical joints shall be 2.5-0.5 cm wide and the bed joints - 1 ± 0.5 cm wide.

3.177. . In lack of proper quality facing blocks the piers can be covered with facing of natural frost-resistant stone with compression strength not lower than 59 MPa (600 kgf/cm2), during heavy ice drift – not lower than 98 MPa (1000 kgf/cm2), provided feasibility study availability. The natural stone facing design should provide the possibility to produce it by industrial methods.

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3.178. *. Reinforced concrete legs can be connected to cross-bar (caps) pier members by means of in-situ casting of reinforcement free lengths in recesses and holes. At this, walls of sleeve-type shoes shall be reinforced at a rate for action of longitudinal and transverse forces.

Reinforcement free lengths brought into recess or hole should be long not less than 20 bar diameters, the concrete of a leg or pile should not enter grillage or cross-bar more than 5 cm.

3.179. *. The designing of mass piers and abutments shall provide the arrangement of reinforced concrete heads not less than 0.4 m thick. Element parts (cross-bars, caps, etc.) in place of transferring to them the pressure from span decks shall be reinforced with additional indirect reinforcement required as rated for local compression. These parts and also cast-in-place butt joints of span decks shall exclude places where penetrating water can stagnate. In places of expansion joints the upper layer of concrete of the piers should provide a slope (not less than 1:10), ensuring water runoff. Slope of top of pier heads and cross-bars shall be arranged during the placing the concrete for them.

3.180. *. Load of bearing parts of span decks at availability of slopes on upper surfaces of mass piers, but for railway bridges – in all cases, shall be transferred to reinforced concrete bridge seats. Height of these bridge seats shall give raising of their top face above the pier not less than to 15 cm. Distance from lower slabs of bearing parts to side faces of bridge seats or to side faces of reinforced concrete members (cross-bars, caps, etc.) should be not less than 15 cm. Distance from bridge seats faces to head faces shall be specified taking into consideration the possibility to install jacks to hoist the span decks ends and be equal in cm not less than:

a) along the bridge 15 - with decks from 15 to 30 m; 25 - with decks from 30 to 100 m; 35 - with decks over 100 m; b) across the bridge:

with round form of the head from the angle of the bridge seat to the nearest head face – not less than indicated in point a); with rectangular form of the head, in cm, not less than: 20 - for slab decks: for all decks, except slab ones, with bearing parts: resin -steel – 20; flat and tangential – 30; roll and sector – 50.

3.181. *. Reinforced concrete structures can be used in piers for bridges located on blind creeks, for underpasses, viaducts and trestles; on water courses – provided reinforcing with reinforcing bars and surface protection against possible mechanical damages. Stressed wire reinforcement is prohibited to be applied in piers on water courses. Reinforced concrete piers within water courses shall be protected against abrasion by ice and removing bottom sediments, against damages by ships or rafts as well as against mechanical damages coursed in case of log jam when applied the drift floating method. As a protective measures it is recommended to apply the concrete with improved wear resistance, to make thicker the protective layer of concrete of reinforced concrete members up to 5-7 cm, and for special heavy conditions (heavy drift ice or snag) the reinforced concrete members can be covered with steel plates. The necessity of protection and the method of protection shall be decided in each separate case in dependence on specific conditions by the designing organization.

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STRUCTURE WATERPROOFING 3.182. . All ballast pocket inner surfaces of deck structures of railway bridges and abutments, in highway bridges – all width of deck structure (including side-walks), transition slabs as well as soil-filled surfaces of abutments, culverts (chutes) should be protected against water permeability to surfaces of the concrete.

3.183. Waterproofing system shall be: watertight all over the protected surface; water-, bio-, thermal-, frost- and chemical resistant; continuous and not be damaged in case of possible formation on the protected concrete surface of cracks with opening specified in norms of designing; durable at long action of dead and live loads and possible crippling of the concrete, but for culverts – in availability of fill soil pressure and hydrostatic water pressure; watertight in place of covering the sling holes and in place of conjunction with sides of ballast pockets as well as with water diversion and protection devices, expansion joints structures, side-walk blocks, cornices, railings, poles, etc.

3.184. Waterproofing system and its material shall be applied on the base of requirements to ensure operation reliability of waterproofing within the ambient air temperature range in the region of construction (as per SNiP 2.01.01-82) from the absolute maximum to mean value of the most cold day-and-nights. When specified waterproofing system of ballast pockets and roadway of deck structures of bridges, abutments, culverts it should be considered also the other features of climate conditions in the region of construction. With proper study the deck structures of highway bridges can apply the waterproofing system made of frost-resistant hydrophobic concrete reinforced with steel mesh; the railway bridges, in case of absence of ballast and aggressive medium, can apply coatings with waterproof paints as waterproofing.

3.185. *. The leveling and protective layers shall be made of concrete with fine aggregate. Grade of concrete as per strength shall be specified for bridges not less than B25 and for culverts not less than B20. The leveling layer shall be reinforced.

3.186. . Other waterproofing types for deck structures, abutments and culverts corresponded to requirements of items 3.183 and 3.184 can be applied in the established order.

4) STEELWORK GENERAL PROVISIONS

4.1. The type of version of steel span structures, piers and culverts, depending on the value of design minimum temperature, shall be selected in conformity with Table 46.

Table 46 Design minimum temperature, o C Type of version up to –40 inclusive Common from -41 to –50 inclusive Northern A Below –50 Northern B

4.2. *When designing bridge steel structures it is necessary : • to choose the best from technical and economic points of view schemes, systems and designs of

span structures, sections of members, efficient structural shapes, and effective steel quality; • to use, as a rule, standardized typical structures and standard members and parts (expansion joints

devices, different operational parts, etc.); • to provide integrated adaptability to manufacture including labor costs of the plants and at the

erection sites, possibility of in-line production, conveyer or big-sized blocks assembly; • irrespective of design minimum temperature and purpose of a bridge to provide the use of welded

prefabricated members connected with high-tension bolts, as a rule. To use welded and composite weld-and-bolt field joints reasonably, taking into account general technology of erection and other

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conditions, but the use of joints in railway and combined bridges should be approved by the Ministry of Railway Communication.

• to provide possibility of inspection, cleaning, painting and repair of structures; to exclude zones inside thereof where water can accumulate and ventilation is not enough; to provide air tightness of closed sections, members and blocks;

• to indicate in KM working drawings of steel structures the quality of steel and materials of joints as well as all necessary additional requirements provided by standards and specifications;

• to observe norms of SNiP 2.03.11-85 and SNiP 3.04.03-85 and requirements of guide technical document “ Bridge Steel Structures. Varnish-and-Paint Coatings” (Mintransstroy, the Ministry of Railway Communication, 1975).

4.3. * Bridge steel structure members should have minimal sections meeting the requirements of the present Norms, taking into account the acting range of rolled stock. When designing composite sections of lattice truss members as per strength and stability the understressing shall not exceed 5 %.

MATERIALS AND SEMIFINISHED ITEMS 4.4. * In steel structures of bridges and culverts of common version the following shall be used: a) for members of rolled metal1 - steel in accordance with Table 47*; b)* for suspended, cable-stayed and prestressed span structures: twisted steel ropes with metal core subjected to prestretching with force equal to the half of breaking load of the whole rope, stipulated by the state standards or technical requirements (but if the given force is not indicated in the state standards it is equal to the half of assembly strength of twisted rope); enclosed load carrying ropes 30-70 mm in dia according to technical requirement ТУ14-4-1216-82; single-stranded rope as per GOST 3064-84 made of round galvanized wire , group ЖС, 2.6 mm in dia and more, by Group; bundles and ropes made of parallel galvanized wires as per GOST 3617-71; c) for metal corrugated pipes - sheet wave profiles made of steel 15cп according to ТУ 14-2-207-76. d)* for cast parts - castings of Group III made of steel 25Л, 30Л, 35Л, 20ГЛ, 20ФЛ, 35ГЛ according to GOST 977-88 and steel 35XH2МЛ according to ТУ 24-1-12-181-75; e)* for hinges, rollers, hinged bolts and fill plates under rollers - forging of: Group IV-КП 275 GOST 8479-70 steel Ст 5сп2-III as per GOST 535-88 and GOST 14637-89; Group IV-КП 315 GOST 8479-70 steel 35-a-T as per GOST 1050-88; Group IV-КП 315 GOST 8479-70 steel 30Г-2-Т as per GOST 4543-71;

Group IV-КП 345 GOST 8479-70 steel 35Г-2-Т as per GOST 4543-71; Group IV-КП 785 GOST 8479-70 steel 40XH2MA-2-2-T as per GOST 4543-71;

Group IV-КП 1200 steel 40X13 as per GOST 5632-72; Group IV-КП 245 GOST 8479-70 steel 265-III-09Г2С as per GOST 19281-89 with pad weld in conformity with requirements for steel 40X13 as per GOST 5632-72;

1 Plates, wide-strip universal, standard sections, bars, pipes and roll-formed sections shall be made of steel with the requirement of weldability, excluding rolled-stock for bolts, nuts, washers and for members without welded joints.

SNiP 2.05.03-84 Page 107

Table 47 S tee l of load carrying e lements of welded decks , pie rs and maintenance devices used in ready-made and fie ld joints

Type of other welded joints and high-tens ion bolts vers ion

butt welds made by machine welding in vertical pos ition on the members from pla te s tee l S tee l qua lity S ta te s tandard

thickness of rolled s tock, mm

thickness of S tee l qua lity S ta te s tandard number additiona l requirements

rolled s tock,

mm number additiona l requirements

type of rolled s tock

Common 8-50 15ХСНД-2 GOST 6713-91 as per note 3 to Table

1*; Any 16Д GOST 6713-91 no up to 20 incl.

items 2.2.7, 2.2.9 sheet s tee l 15ХСНД GOST 6713-91 as per note 3 to Table

1*; 8-15 8-40 10ХСНД-2 GOST 6713-91 ditto items 2.2.7, 2.2.9

4-50 390-14Г2АФД-14 GOST 19281-

89 as per item 1.4* 15ХСНД-2 GOST 6713-91 ditto 16-50

4-32 390-15Г2АФДпс-14 GOST 19281-

89 ditto 10ХСНД GOST 6713-91 ditto 8-15 10ХСНД-2 GOST 6713-91 ditto 16-40

390-14Г2АФД-13 GOST 19281-

89 as per item 1.4* 4-50

390-15Г2АФДпс-13 GOST 19281-

89 ditto 4-32

s tructural 15ХСНД GOST 6713-91 as per note 3 to Table

1*; 8-32 Shapes items 2.2.7, 2.2.9 10ХСНД GOST 6713-91 ditto 8-15

Northern A 8-50 15ХСНД-3 GOST 6713-91 as per note 3 to Table

1*; sheet s tee l 15ХСНД-2 GOST 6713-91 ditto 8-50 items 2.2.7, 2.2.9 10ХСНД-2 GOST 6713-91 ditto 8-40

8-40 10ХСНД-3 GOST 6713-91 ditto 390-14Г2АФД-14 GOST 19281-

89 as per item 1.4* 4-50

4-50 390-14Г2АФД-15 GOST 19281-

89 as per item 1.4* 390-15Г2АФДпс-14 GOST 19281-

89 ditto 4-32

4-32 390-15Г2АФДпс-15 GOST 19281-

89 ditto s tructural 15ХСНД-2** GOST 6713-91 as per note 3 to Table

1*; 8-32 Shapes items 2.2.7, 2.2.9 10ХСНД-2** GOST 6713-91 ditto 8-15

Northern Б 8-40 10ХСНД-3 GOST 6713-91 as per note 3 to Table

1*; sheet s tee l 10ХСНД-3 GOST 6713-91 as per note 3 to Table

1*; 8-40

items 2.2.7, 2.2.9;

4.3*** items 2.2.7, 2.2.9;

4.3*** s tructural 15ХСНД-3** GOST 6713-91 ditto 8-32 Shapes 10ХСНД-3** GOST 6713-91 ditto 8-15 * Steel of 14?2??? and 15?2????? Qualities are to be used only in highway, urban and pedestrian bridges. ** In all-puprose bridges angles as per GOST 8509-72 and GOST 8510-72 are allowed to be used without thermal treatement, rolled stock of Category I, as per GOST 6713-91. In structures of highway, urban and pedestrian bridges of Northern version ? and ? it is allowed to use I-, T-bars, channels without thermal treatement

SNiP 2.05.03-84 Page 108

under condition that requirements on impact strength are observed at the temperature -60º and -70º C accordingly *** It is required to test each sheet only under the design minimal temperature -60ºC and below.

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f) high-tension bolts as per GOST 22353-77, high-tension nuts as per GOST 22354-77, washers for high-tension bolts as per GOST 22355-77 with general technical requirements for them as per GOST 22356-77; g) for welding of structures - welding materials provided by “Instruction on Technology of Automatic and Manual Welding in Bridge Steelwork Prefabrication” (Mintransstroy, 1980); h)* for connection of bridge deck members, parapets and inspection chambers - steel bolts as per GOST 7798-70 of strength class 4.6 as per GOST 1759.4-87 (with tests according to items 6.2 and 6.6), and nuts as per GOST 5915-70 of strength class 4 and 5 as per GOST 1759.5-87 (bolts and nuts are made of killed steel only) as well as bolts and nuts of steel Ст3сп4 as per GOST 535-88 according to special technical requirements; i)* for fixing of bearing parts to decks and steel supports - steel bolts as per GOST 7798-70 and nuts as per GOST 5915-70 of steel 09Г2 according to ТУ 14-1-287-72, 295-III-09Г2-4 and 295-III-09Г2C-4 as per GOST 19281-89, of steel 40X as per GOST 4543-71 according to special technical requirements. j)* for fastening of bearing parts to concrete piers and foundations - foundation (anchor) bolts as per GOST 24379.0-80 and GOST 24379.1-80 of steel 20-г-Т as per GOST 1055-88 and steel 295-III 09Г2C-4 as per GOST 19281-89, and also of steel 40X as per GOST 4543-71 according to special technical requirements; nuts as per GOST 5915-70 for bolts less than 48 mm in dia and as per GOST 10605-72 for bolts more than 48 mm in dia, strength classes 4 and 5 as per GOST 1759.5-87 (only of killed steel) and also of steel 20-г-T, strength class 6 as per GOST 1759.5-87 (only of killed steel) - for bolts of steel 295-III 09Г2C-4, strength class 10 and 12 as per GOST 1759.5-87 - for bolts of steel of 40X. k) for casting the wire rope ends in anchorages - alloy ЦАМ9-1.5Л as per GOST 21437-75; l)* for elements of wire rope anchors - steel 295-Ш 09Г2С-4 as per GOST 19281-89 and also steel 20-б-T and steel 45-б-T, normalizing state, as per GOST 1050-88; m) for gaskets in between wire ropes and also in between ropes and anchor elements, back-stay devices, grips, hanger clamps and other elements - sheets as per GOST 21631-76 or strips as per GOST 13726-78, not less than 1 mm thick made of aluminum АД and АД1 brands as per GOST 4784-74. Notes: 1. Carrying welded members of sidewalks and inspection devices (of cantilevers and sidewalk beams, posts and handrails of parapets, beams of stairs, crossing platforms, inspection bogies and lifting cradles) as well as members of bridge deck can be made of steel Ст3сп5; and the mentioned above members less welded joints – of steel Ст3сп4 as per GOST 535-88 and GOST 14637-89. Rolled products up to 10 mm thick inclusive can be made of semi-killed steel of the same categories. In doing so, the round pipes can be used without any restrictions, but rectangular welded pipes shall observe the requirements of SNiP III-18-75 on radius of bending for structures reacting a dynamic load. Mechanical properties of metal pipes shall be specified in the design and guaranteed by Manufacturing Plant. 2. In handrails and inspection devices the angles with leg of 70 mm and less can be made of steel Ст3пс2 as per GOST 535-88. 3. Casings (housings) of bearing parts can be made of Steel Ст0 as per GOST 14637-89. 4. Steel СТ3кп2 as per GOST 535-88 and GOST 14637-89 can be used for making the idle gaskets and members of handrails, and steel Ст3пс2 as per GOST 14637-89 - for making the floors and fittings of passages for inspection.

4.5. *In steel structures of bridges and culverts of northern version the following shall be used: a) materials and semifinished items listed in paragraph 4.4* a, b*, d*-g, k-m. b) for metal corrugated pipes - sheet wave profiles of steel 09Г2Д in accordance with ТУ 14-2-207-76;

SNiP 2.05.03-84 Page 110

c) to connect members of bridge deck, handrails and inspection devices - steel bolts as per GOST 7798-70 , strength class 4 and 6 as per GOST 1759.4-87 (with tests according to items 6.2 and 6.6) of diameter less than 22 mm, and bolts of steel 09Г2 according to ТУ 14-1-287-72 by special technical conditions, of diameter 22 mm and more; nuts as per GOST 5915-70, strength class 4 and 5 as per GOST 1759.5-87 (bolts and nuts are to be made of killed steel only). d)* to fasten bearing parts to decks and steel piers - steel bolts as per GOST 7798-70 and nuts as per GOST 5915-70 of steel 09Г2 according to ТУ 14-1-287-72, 295-III 09Г2-6 and 295-III 09Г2С-6 as per GOST 19281-89 and 40X as per GOST 4543-71 by special technical conditions; e)* for fasten bearing parts to concrete piers and foundations - foundation (anchor) bolts as per GOST 24379.0-80 and GOST 24379.1-80 of steel 295-III 09Г2-6 and 295-III 09Г2С-6 as per GOST 19281-89 and also of steel 09Г2 according to ТУ 14-1-287-72 and steel 40X as per GOST 4543-71 by special technical conditions; nuts as per GOST 5915-70 for bolts diameter less than 48 mm and as per GOST 10605-72 for bolts diameter more than 48 mm - of strength class 6 as per GOST 1759.5-87 (of killed steel only) - for bolts of steel 09Г2-8, 09Г2С-8, 09Г2, of strength class 10 and 12 as per GOST 1759.5-87 - for bolts of steel 40X. Notes: 1. Notes 3 and 4 to item 4.4* are applied to bridge structures of northern version. 2. It is allowed to use steel 345-10Г2СIД-4, 345-10Г2CI-4, 325-09Г2СД-4, 325-09Г2С-4, 295-09Г2Д-4, 295-09Г2-4 and 325-14Г2-4 as per GOST 19281-89 for sidewalk carrying members, inspection devices and bridge deck members. In doing so, the round pipes can be used without any restrictions, but rectangular welded pipes shall observe the requirements of SNiP III-18-75 on radius of bending for structures made of low-alloyed steel reacting a dynamic load. Mechanical properties of metal pipes shall be specified in the design and guaranteed by Manufacturing Plant. 3*. It is allowed to use angles with leg 70 mm and less made of steel Ст3пс2 as per GOST 535-88 for sidewalk crash barriers members and inspection devices.

DESIGN CHARACTERISTICS OF MATERIALS AND JOINTS 4.6. *Rolled stock designed resistance of different types of stressed state shall be determined by formulae given in Table 48*.

Table 48 Stressed state

Designed resistance of rolled stock

Tension, compression and bending: by yield point Ry = Ryn / γm by ultimate resistance Ru = Run / γm Shear Rs = 0.58 Ryn / γm Bearing stress of end face (if fitting is available)

Rp= Run / γm

Local bearing stress in cylindrical hinges (journals) in case of tight contact

Rtp = 0.5 Run / γm

Diametrical compression of rollers (in case of free contact in structures with limited mobility)

if Run ≤ 600 MPa (5886 kgf/cm2 ) Rcd = 0.25 Run / γm’ if Run > 600 MPa (5886 kgf/m2 ); Rcd = [0.042·10-6(Run -600)2 +0.025] Run / γm' MPa ; Rcd = [0.0438·10-8(Run-5886)2 +0.025] Run / γm' kgf/cm2

Tension by thickness of rolled products tτ if t is up to 60 mm

Rth = 0.5 Run / γm

Note: γm is a partial safety factor for material strength determined according to item 4.7*.

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4.7. * Values of partial safety factor γm for material strength for rolled stock shall be accepted in accordance with Table 49*. Characteristic and designed resistance values of rolled stock of steel as per GOST 6713-91, steel 390-14Г2АФД, 390-15Г2АФДпс as per GOST 19281-89 and steel 40X13 as per GOST 5632-72 shall be accepted in accordance with Table 50*. Designed resistance of rolled stock as per GOST 535-88, GOST 14637-89 and GOST 19281-89 shall be accepted equal to yield point, indicated in the given Standards, divided to partial safety factor γm for material strength as per Table 49*.

4.8. Designed resistance values of castings from carbon and alloyed steel shall be accepted in accord with Table 51*.

4.9. Designed resistance values of forging from carbon and alloyed steel shall be accepted in accordance with Table 52*.

4.10. Designed resistance values of welded joints for different types of connections and stressed states shall be determined by formulae given in Table 53. Designed resistance values of butt joints of members of steel with different rated resistance shall be taken as for butt joints of steel with smaller rate resistance. Designed resistance of metal of fillet welds shall be accepted according to Appendix 2 of SNiP II-23-81*.

4.11. * Designed resistance of single-bolt joints shall be determined by formulae given in Table 54*. Designed resistance against shear and tension of bolts shall be accepted according to Table 55*. Designed resistance against bearing of members connected with bolts shall be determined as per Appendix 2 of SNiP II-23-81*.

4.12. * Designed resistance against tension of foundation (anchor) bolts Rba shall be determined by formula Rba = 0.4 Run (138) Designed resistance against tension of foundation (anchor) bolts shall be taken according to Table 56*.

4.13. Designed resistance against shear for the alloy ЦАМ 9-1.5Л shall be taken equal to 50 MPa (500 kgf/cm2).

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Table 49 State Standard (quality of steel or yield point value) Partial safety factor for material strength, γm

GOST 535-88 and GOST 14637-89 [Ст3сп, Ст3пс, Ст3кп] GOST 19281-89 and GOST 19282-89 [up to 380 MPa (39 kgf/mm2 )]

1.05

GOST 19281-89 and GOST 19282-89 [more than 380 MPa (39 kgf/mm2 )] 1.10 GOST 6713-91 [16Д] 1.09 GOST 6713-91 [15XCHД] 1.165 GOST 6713-91 [10XCHД] 1.125

Table 50

Quality of steel

State standard Rolled stock Thickness of rolled stock1, mm

Characteristic resistance2, MPa (kgf/mm2 )

Designed resistance3, MPa (kgf/cm2)

by yield point Ryn by ultimate strength Run

by yield point Ry by ultimate strength Ru

16Д GOST 6713-91 Any up to 20 235 (24) 370 (38) 215 (2200) 340 (3450) 16Д GOST 6713-91 Any 21-40 225 (23) 370 (38) 205 (2100) 340 (3450) 16Д GOST 6713-91 Any 41-60 215 (22) 370 (38) 195 (2000) 340 (3450) 15XCHД GOST 6713-91 Any 8-32 340 (35) 490 (50) 295 (3000) 415 (4250) 15XCHД GOST 6713-91 Plate 33-50 330 (34) 470 (48) 285 (2900) 400 (4100) 10XCHД GOST 6713-91 Any 8-15 390 (40) 530 (54) 350 (3550) 470 (4800) 10XCHД GOST 6713-91 Plate 16-32 390 (40) 530 (54) 350 (3550) 470 (4800) 10XCHД GOST 6713-91 Plate 33-40 390 (40) 510 (52) 350 (3550) 450 (4600) 390- 15Г2АФДпс GOST19282-89 Plate 4-32 390 (40) 540 (55) 355 (3600) 490 (5000) 390- 14Г2АФД GOST 19282-89 Plate 4-50 390 (40) 540 (55) 355 (3600) 490 (5000) 40X13 GOST 5632-72 Round up to 250 1200 (122) 1540 (157) 1050 (10700) 1365 (13900)

1Thickness of standard sections shall be specified by thickness of a leg. 2Characteristic resistance shall be specified by minimal values of yield point and ultimate strength, given in GOST 6713-91 in kgf/mm2 . Characteristic resistance values in MPa are computed by multiplication of corresponding values by multiplier 9.80665 and by rounding-off to 5 MPa. 3Designed resistance to tension, compression and bending Ry and Ru are indicated herein. Other rated resistance values are calculated by formulae of Table 48*. Designed resistance values are computed by division of rated resistance values to partial safety factor for material strength, according to Table 49*, and by rounding-off to 5 MPa.

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4.14. Design tension strength Rbh of high-tension bolts as per GOST 22353-77* and GOST 22356-77* shall be determined by formula Rbh = 0.7 Rbun (139) where Rbun - the least ultimate rupture strength of high-tension bolts as per GOST 22356-77*.

4.15. * Values of friction coefficient µ on contact surfaces of elements in frictional connections1 shall be specified as per Table 57*. The contact surface treatment method must be indicated in KM drawings.

4.16. Design tension strength Rdh of high-tensile steel wire used in bundles or ropes composed of parallel laid wires shall be determined by formula Rdh = 0.63 Run (140) where Run - the least ultimate rupture strength of wire in accordance with State standards or technical conditions.

4.17. * When determining designed resistance of twisted steel ropes with metal core, value of the rope breaking load, stipulated by the State standard and technical conditions for ropes (in absence of it in the State Norms it will be a value of assembly strength of twisted rope) and safety factor γm = 1.6 shall be considered.

4.18. * Modulus of elasticity and shearing modulus of rolled steel, cast steel, bundles and ropes composed of parallel laid wires shall be specified in accordance with Table 58*. Elasticity modulus of twisted galvanized steel ropes with metal core, subject to the prestretching caused by the force applied and equaled to the half of breaking load of the whole rope, shall be taken in accord with Table 59.

1 Connections are deemed to be frictional when forces are transferred only by friction forces on contact planes of elements to be connected; friction appears due to the tensioning of high-tension bolts.

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Table 51* Stress state Designed resistance, MPa (kgf/cm2), of castings

Symbols quality of steel 25Л 30Л 35Л 20ГЛ 20ФЛ 35ХН2МЛ 35ГЛ

Tension, compression, and bending

Ry 175 (1800) 190 (1950) 205 (2100) 205 (2100) 220 (2250) 400 (4100) 220 (2250)

Shear Rs 105 (1100) 115 (1200) 125 (1300) 125 (1300) 130 (1350) 240 (2450) 130 (1350) Bearing stress of end face (if fitting is available)

Rp 265 (2700) 300 (3050) 315 (3200) 345 (3500) 315 (3200) 440 (4500) 345 (3500)


Rtp 125 (1300) 145 (1500) 155 (1600) 170 (1750) 155 (1600) 222 (2250) 170 (1750)

Diametrical compression of rollers (free contact in structures with limited mobility)

Rcd 7 (70) 7.5 (75) 8 (80) 9 (90) 8 (80) 11 (110) 9 (90)

Table 52*

Stress state Design resistance, MPa (kgf/cm2) of forgings of Group IV Symbols if strength category (steel quality) is: КП275

(Ст5сп2) КП245 (20-а-Т)

КП315 (35-а-Т)

КП345 (45-а-Т)

КП315 (30Г-2-Т)

КП345 (35Г-2-Т)

КП785 (40ХН2МА-

2-2-Т)

КП1200 (40Х13)

Tension, compression and bending: Ry 215(2200) 205(2100) 260(2650) 290(2950) 260(2650) 280(2850) 605(6150) 1050(10700) Shear Rs 120(1250) 115(1200) 145(1500) 165(1700) 145(1500) 160(1650) 350(3550) 610(6200) Bearing stress of end face (if fitting is available)

Rp 325(3300) 310(3150) 395(4000) 435(4400) 395(4000) 420(4250) 905(9200) 1365(13900)


Rtp 160(1650) 150(1550) 195(2000) 215(2200) 195(2000) 205(2100) 450(4600) 685(6950)

Diametrical compression of rollers (free contact in structures with limited mobility)

Rcd 8(80) 7.5 (75) 10(100) 11(110) 10(100) 10(100) 23(230) 85(860)

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Table 53

Welded joints Stress state Design resistance of welded joints Butt joints Compression.

Tension and bending when automatic, semiautomatic or hand welding with physical quality control of joints carried out by: by impact strength by ultimate strength Shear

Rwy = Ry Rwu = Ru Rws = Rs

With fillet welds

Section (conditional): along metal of joints

Rwf = 0 55.Rwun

wmγ

along metal of fusion line Rwz = 0.45 Run

Notes: 1. For manual welded joints the values Rwun shall be taken equal to values of ultimate rupture strength of joint metal, which are given in GOST 9467-75*. 2. For joints made with semiautomatic or automatic welding the values Rwun shall be taken in accordance with Section 3 of SNiP II-23-81*. 3. Safety factor for material strength of joint γwm shall be equal to 1.25.

Table 54*

Stress state Design resistance of single-bolt connections to shear and tension of bolts, with strength class or steel quality to bearing stress of elements to be 4.6; Ст3сп4; 09Г2; 295-09Г2-4; 295-

09Г2-6; 325-09Г2С-4; 325-09Г2С-6

40Х connected, of steel with normative yield point up to 440 MPa

(4500 kgf/cm2) Shear

Rbs = 0.38 Rbun Rbs = 0.4 Rbun ----

Tension

Rbt = 0.42 Rbun Rbt = 0.5 Rbun ----

Bearing stress: a) bolts of A class of accuracy ---- ----

Rbp = ( . )0 6 410+RE

Runun

b) bolts of B and C class of accuracy ---- ---- Rbp = ( . )0 6 340+

RE

Runun

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Table 55*

Stress state Designed resistance, MPa (kgf/cm2) of bolts with strength class or steel quality

Symbol 4.6 Ст3сп4 09Г2; 295-09Г2-4;

295-09Г2-6 325-09Г2С-4; 325-09Г2С-6

40Х

Shear

Rbs 145 (1500) 140 (1450) 165 (1700) 175 (1800) 395 (4000)

Tension

Rbt 160 (1650) 155 (1600) 185 (1900) 195 (2000) 495 (5000)

Table 56*

Bolts diameter d, mm

Designed resistance, MPa (kgf/cm2) of foundation (anchor) bolts of steel of quality

20 09Г2; 295-09Г2С-6

325-09Г2С-6 40Х

12-20 160 (1650) 175 (1800) 185 (1900) --- 16-27 --- --- --- 430 (4400) 21-32 160 (1650) 175 (1800) 180 (1850)

30 --- --- --- 370 (3800) 36 --- --- --- 295 (3000)

33-60 160 (1650) --- 180 (1850) --- 42 --- --- --- 255 (2600) 48 --- --- --- 235 (2400)

61-80 160 (1650) --- 175 (1800) --- 81-100 160 (1650) --- 170 (1750) ---

101-160 160 (1650) --- 170 (1750) --- 161-250 160 (1650) --- --- ---

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Table 57* Method of treatment of contact surfaces

in frictional connections Friction coefficient µ

1. Sandblast or shotblast treatment of two surfaces with quartz sand or shot - excluding the further preservation

0.58

2. Treatment of one surface with quartz sand or shots, preserving it with polymer adhesive and coating with silicon carbide powder, and treatment with steel brushes of another surface without preservation.

0.50

3. Torch treatment of both surfaces without preservation 0.42 4. Treatment of both surfaces, with steel brushes, without preservation 0.35 5. Shot-blasting method of treatment of both surfaces, with shots, without further preservation

0.38

6. Shot-blasting method of treatment of both surfaces, with shots, followed with torch heating (up to the temperature 250-300°C) in the ring zones nearby holes, having the area not less than area of the washer

0.61

Table 58* Semifinished items Modulus of elasticity E or shearing

modulus G, MPa (kgf/cm2)

1. Rolled steel and cast steel E = 2.06 ⋅ 105 (2.1 ⋅ 106) 2. Ditto G = 0.78 ⋅ 105 (0.81 ⋅ 106) 3. Bundles and ropes from parallel laid galvanized wires as per GOST 3617-71.

E = 2.01 ⋅ 105 (2.5 ⋅ 106)

Elasticity modulus of twisted galvanized steel ropes with metal core, subject to the prestretching caused by the force applied and equaled to the half of breaking load of the whole rope, shall be taken in accordance with Table 59.

Table 59 Ropes Twist ratio Modulus of elasticity E,

MPa (kgf/cm2)

Single-stranded ropes as per 6 1.18 ⋅ 105 (1.20 ⋅ 106) GOST 3064-80 and enclosed load carrying ropes as per ТУ 14-4-1216-82

8 10 11

1.45 ⋅ 105 (1.47 ⋅ 106) 1.61 ⋅ 105 (1.63 ⋅ 106) 1.65 ⋅ 105 (1.67 ⋅ 106)

12 1.70 ⋅ 105 (1.73 ⋅ 106) 14 1.75 ⋅ 105 (1.78 ⋅ 106) 16 1.77 ⋅ 105 (1.80 ⋅ 106)

WORKING MODE AND PURPOSE OF STRUCTURES 4.19. *When designing steel structures and bridge connection members the following shall be considered: safety factor for purpose γn taken equal to γn = 1.0; safety factor γu = 1.3 for structure members designed by strength using designed resistance Ru; coefficient of working mode m taken in accordance with Table 60* and 81 and sub-sections of the present Norms; and for wire ropes in zones of bending in back-stay devices, clamps, ties, clips, and anchors - in accordance with Compulsory Appendix 14.

Table 60 Field of application Coefficient of

working mode, m

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1. Members and connections thereof in decks and piers of railway and pedestrian bridges when designed on operating loads

0.9

2. Ditto, when designed on loads, appearing under fabrication, transportation and erection of the members

1.0

3. Members and connections thereof in decks and piers of railway and pedestrian bridges when designed on operating loads and loads, appearing under fabrication, transportation and erection of the members

1.0

4. Ropes of flexible bearing members in cable-stayed and suspended bridges

0.8

5. Ropes of stressed members of prestressed structures 0.9 6. Compression and tensile members from single profiles, mounted by one leg (or web):

unequal angle, mounted by the shorter leg 0.7 unequal angle, mounted by the longer leg 0.8 Equal leg angle 0.75 rolled and composed channel, mounted by the wall, or T-

bar, fastened by the leg 0.9

7. Members and weld joints thereof in decks and piers of Northern version Б

0.85

Notes: In relevant cases the values of working mode coefficient for items 1, 2 and 3 are applied together with values of coefficient for items 4-7. In relevant cases the value of working mode coefficient for the item 7 is applied together with coefficient values for items 4-6. In otherwise cases it shall be used m = 1.0 in the formulae.

DESIGNS GENERAL PROVISIONS

4.20. Design diagram of a structure shall be accepted in compliance with its designed geometrical diagram, at this, camber and deformations under load are ignored, as a rule. Forces in members and displacement of steel bridge members are determined from the condition of their behavior with gross sections. Geometrical non-linearity, caused by the structure members displacement, shall be taken into account in the design of the systems in which geometric non-linearity causes changes in forces and displacement more than for 5 %. When designs include non-linearity it is necessary to determine changes in direction of forces actions, connected with general deformation of the system (tracing effect). When determining forces in structural members the welded and frictional connections with high-tension bolts shall be considered as inelastic ones. When designing cable-stayed and suspension bridges with flexible twisted single-stranded metal-core rope and enclosed ropes subjected to prestretching as per item 4.4*, the transverse and longitudinal creep of mentioned ropes shall be considered as per provisions of items 4.34 and 4.35.

4.21. Rigid connections of members in lattice girders nodes can be assumed in design as the hinged ones if with this assumption the structure remains its rigidity, at this, for main girder the ratio of cross-sectional height to length of member shall not exceed 1:15, as a rule. Additional stresses in truss chords from hangers deformation shall be considered not depending upon the ratio of cross-sectional height to member length of chord. Allowance of nodes rigidity in lattice girders can be carried out with approximation methods, at this axial forces can be determined by hinge design diagram.

SNiP 2.05.03-84 Page 120

4.22. *For an axis of span structure member it is taken a line connecting the centers of gravity of its sections. When determining location of the center of gravity of the section, its weakening by the bolted joint holes is ignored, but weakening by perforation is included and taken constant all over the whole length of the member. When the axis of through truss member is displaced relative to the line connecting the centers of nodes the eccentricity shall be considered in the design if it exceeds: for П-shaped, box, double-channeled, and I-beam members - 1.5 % of beam depth; for T-beam and H-shaped members - 0.7% of beam depth. Bending moments of member axes displacement are distributed among all members of the node in proportion to their rigidity and in inverse proportion to the length. In doing so each bending moment shall be taken equal to the product of eccentricity into the maximum value of force in the given member of the basic design diagram. It is allowed to ignore the eccentricity appeared in bracing members composed of angles with bolted connections, centered by marks being the nearest to the back edge.

4.23. Distribution of live load in members of multibeam span structures with continuous girders united with rigid cross bracing when length-to-width ratio is more than 4 can be determined by thin-walled bar theory, accepting the hypothesis of non-deformability of cross section contour. In all other cases it is necessary to consider the deformations of cross section contour.

4.24. On the stage of designing it is necessary to provide spatial rigidity, strength, general and local stability of span structures and piers as a whole, blocks, individual members, their parts, details and joints under the loads action occurred during fabrication, transportation and erection; and under the operational loads action - endurance shall be provided as well. For members weakened by common bolt holes the designs of strength and endurance should use net sections and designs of stability and rigidity should use gross sections. In designs of members with frictional connections on high-tension bolts for endurance, stability and rigidity the gross sections shall be used, in designs for strength the net sections shall be used with allowance for that half force in considered section applied to the given bolt has been already transferred by the forces of friction. Geometrical characteristics of net section of structural members shall be defined, determining the most unfavorable weakening.

STRENGTH DESIGN CENTRALLY TENSIONED AND CENTRALLY COMPRESSED MEMBERS

4.25. *The strength design for members subject to central tension or compression by force N shall be calculated by formula NA

R mn

y≤ (141)

Here and in items 4.26*- 4.32 m - coefficient of working mode, specified in Table 60*.

FLEXURAL MEMBERS 4.26. *The strength design for members subjected to bending in one of the main planes shall be calculated by formula

mRWM

yh

≤∂

(142)

where ∂ - coefficient accounting for the limited development of plastic deformation in section and determined by formulae (143) and (144*) under the provision that all requirements of item 4.32 are fulfilled. Wn - here and further in strength designs the minimal moment of resistance of net section determined taking into consideration an effective width of chord bef .

SNiP 2.05.03-84 Page 121

At the simultaneous action of moment M and transverse force Q in section the coefficient ∂ shall be calculated by formulae if τm ≤ 0.25Rs ∂ = ∂1; (143) when 0.25 Rs < τm ≤ Rs

∂ ∂α

=− +

+1

21 21 2

aba

;

when 0≤ ∂ ≤ ∂1 (144*)

where ∂1 = coefficient accepted for I-section, box and T-sections in accordance with Table 61, for annular sections the coefficient is equal to 1.15, for entire rectangular and H-shape sections - 1.25;

τm = Q

h tw w- the average tangential stress in the beam web,

α =QQu

; aAA

f

w=

Σ

Σ; b = −1 0 25 2. α - for box sections;

b = −1 0 0625 2. α - for I-sections; here Qu - the ultimate transverse force calculated by formula

QR m It

Sus=

∂2

where ∂2 is accepted by formula (160). When calculating Wn the effective width of chord bef shall be calculated by formula bef = Σvbi (145) where v - coefficient of reduction of unevenly distributed stresses over the width of chord bi parts to the conventional evenly distributed stresses over the whole effective width of chord bef taken in accord with Table 62; bi - chord part width located in considered section between two points with maximal stresses σmax (then bi = b), or between such point and the chord edge (bi = bk), in this case the following requirements shall be met: b ≥ 0.04l and bk ≥ 0.02l (otherwise v = 1). l - length of simply supported beam span or distance between points of zero moments in continuous beam.

Table 61 Af min Values of coefficient ∂1 with ratio of areas (Af min + Aw) / A , equal to Aw 0.01 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0 1.243 1.248 1.253 1.258 1.264 1.269 1.274 1.279 1.283 1.267 1.243 0.1 1.187 1.191 1.195 1.199 1.202 1.206 1.209 1.212 1.214 1.160 --- 0.2 1.152 1.155 1.158 1.162 1.165 1.168 1.170 1.172 1.150 --- --- 0.3 1.128 1.131 1.133 1.136 1.139 1.142 1.144 1.145 1.097 --- --- 0.4 1.110 1.113 1.115 1.118 1.120 1.123 1.125 1.126 1.069 --- --- 0.5 1.097 1.099 1.102 1.104 1.106 1.109 1.110 1.106 1.061 --- --- 0.6 1.087 1.89 1.091 1.093 1.095 1.097 1.099 1.079 --- --- --- 0.7 1.078 1.080 1.082 1.084 1.086 1.088 1.090 1.055 --- --- --- 0.8 1.071 1.073 1.075 1.077 1.079 1.081 1.082 1.044 --- --- --- 0.9 1.065 1.067 1.069 1.071 1.073 1.074 1.076 1.036 --- --- --- 1.0 1.060 1.062 1.064 1.066 1.067 1.069 0.071 1.031 --- --- ---

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2.0 1.035 1.036 1.037 1.038 1.039 1.040 1.019 --- --- --- --- 3.0 1.024 1.025 1.026 1.027 1.028 1.029 1.017 --- --- --- --- 4.0 1.019 1.019 1.020 1.021 1.021 1.022 1.015 --- --- --- --- 5.0 1.015 1.015 1.016 1.017 1.018 1.018 --- --- --- --- --- Note: 1. For box sections area Aw shall be taken equal to sum of web areas. 2. For T-sections Af min = 0.

Table 62 σmin / σ max Coefficient v σmin / σ max Coefficient v 1.0 1 0.25 0.65 0.7 1 0.20 0.60 0.5 1.85 0.10 0.52 0.33 0.72 0 0.43 In Table 62 σ max , σmin - maximal and minimal stresses in the given part of the chord with width bi, determined by design of a spatial structure in elastic stage. Note: If there are cuts-out in orthotropic plates for installation of tower body, breaks of plates in compartments of multisectional box section, other structure discontinuities, as well as in sections where concentrated forces have been applied, the values of coefficient v shall be determined by special methods.

4.27. Strength design for members, bent in two main planes, shall be calculated: with T-sections and box sections with two axes of symmetry - by formula

MW

MW

R mx

x xnx

y

y yny y∂

ψ∂

ψ+ ≤ ; (146)

with sections of other types - by formula M y

IM x

IR mx

x xn

y

y yny∂ ∂

± ≤ , (147)

where ∂x, ∂y - coefficients determined by formulae (143) and (144*) as independent values for cases of bending relative to axes x and y; ψx, ψy - coefficients determined for: I-sections, having two axes of symmetry - by formulae:

ψ∂x

x

x xn y

MW R m

= ; ψy = 1; (148)

Box sections with two axes of symmetry - by formulae:

ψω

ωxx

x=

+( . ).

;0 7

3 38

2

ψω

ωyy

y=

+( . ).

,0 7

3 38

2

(149)

where

ω∂x

x

x xn y

MW R m

= ; ω∂y

y

y yn y

MW R m

= . (150)

SNiP 2.05.03-84 Page 123

MEMBERS SUBJECT TO EFFECT OF AXIAL FORCE WITH BENDING 4.28. *Strength design for eccentrically compressed, compressed-and-bent, eccentrically tensioned, and tensioned-and-bent members, when bent in one of the main planes shall be calculated by formula NA

MW

R mn n

yψ∂

+ ≤ , (151)

where M - reduced bending moment; ψ - coefficient; ∂ - coefficient, calculated by formulae (143) and (144)*. With elasticity of members λ > 60 for sections being within two mean quarters of the length of the bar hinged at its ends and the total length of the fully fixed bar the reduced bending moment M shall be calculated by formula

MM

NN e

=+

1

1, (152)

where M 1 – moment, acting in the checked section; N - transverse force, acting in the checked section with its own sign (“plus” - means the tension); Ne – Euler’s critical load in the plane of the moment action, calculated for the corresponding fixings of the bar; if λ ≤ 60 it is allowed to take M = M1. The coefficient ψ shall be calculated for: members of I-section, box, and T-sections with one axis of symmetry in accord with Table 63, if stresses in the smaller chord (having area Af, min) are caused by the moment and transverse force of the same signs, and in accord with Table 64* if stresses in the smaller chord are caused by the moment and transverse force of different signs; members of entire rectangular and H-shape sections - by formula

ψ =N

A R mn y; (153)

members of annular section - by formula

ψω

ωπ

= −1

12

( cos ), (154)

where ω =N

A R mn y.

For other sections as well as other fixings of member ends the strength design shall be calculated by formula NA

MyI

R mn xn

y± ≤∂

. (155)

In formulae (153) - (155) the same symbols are used as for formula (151).

4.29. *Strength design for eccentrically compressed, compressed-and-bent, eccentrically tensioned, and tensioned-and-bent members, subjected to bending in two main planes shall be calculated for: members of I-section, box, and T-sections with one axis of symmetry as well as for members of rectangular and annular entire sections - by formula

1δ

ψ∂

NA

MW

R mn

x

x xny+

≤ , (156)

where

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δ∂

= −1M

W R my

y yn y; (157)

Mx, My - reduced bending moments as per item 4.28*; ψ, ∂x, ∂y - coefficients accepted in accord with items 4.28* and 4.26*, at that

ωδ

=N

A R mn y;

for other sections as well as other fixings of members ends the strength design shall be calculated by formula

.mRxI

My

IM

AN

yyny

y

xnx

x

n

≤±±∂∂

(158)

In basic cases, when reduced data are not enough for determination of ∂x and ∂y, the strength design shall be calculated by formula (158) where ∂x = ∂y = 1.

4.30. *Values of tangential stresses τ in sections of webs of flexural members when M=Mx=My=0 shall meet the following requirement

τ∂

= ≤QS

ItR ms

2, (159)

∂τ

τ2 125 0 25= −. . min,

max,

ef

ef (160)

where τmin, ef and τmax, ef - values of minimal and maximal tangential stresses in web section, calculated with assumption of elastic behavior. In case of web weakening by holes of bolt connections the value t in the formula (159) shall be substituted by the following value

t ta d

aef =−

,

In this formula a - bolt spacing; d - diameter of holes.

4.31. * For beam webs designed in items 4.26*-4.29*, the following requirement shall be met σ σ σ σ τ γx x y y xy yR m2 2 23− + + ≤ ' ; τxy ≤ R3 m, (161)

where σx - normal (positive at the compression) stresses parallel to the beam axis, occurred in the checked point (x, y) of the middle plane of the web; σy - the same stresses perpendicular to the beam axis and determined in accord with the Compulsory Appendix 16*; γ’ - coefficient equal to 1.15 if σx = 0 and to 1.10 if σy ≠0; τxy - tangential stress in the checked point of the beam web.

4.32. Members taking forces of different signs, after checking the strength including assumption of development of limited plastic formations (∂>1), shall be checked by the following formula:

( ) ( ) . ,max minσ σ τ τ− + − ≤21 2

23 18R my (162) where σmax, σmin - accordingly maximal and minimal (with their own signs) normal stresses in the checked point, calculated with assumption of material elastic behavior; τ1, τ2 - tangential stresses in the checked point (taking into account their signs), calculated from the same loads as σmax and σmin accordingly.

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If this requirement is not fulfilled the strength design shall be made for the greatest forces for the elastic stage of behavior.

SNiP 2.05.03-84 Page 126

Table 63

Af, min / Value of coefficient ψ at ω Af, max 0.05 0.2 0.4 0.6 0.8 0.95

at Af, max / Aw 0.5 1 2 0.5 1 2 0.5 1 2 0.5 1 2 0.5 1 2 0.5 1 2 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

0.5 0.53 0.55 0.57 0.63 0.68 0.78 0.77 0.85 0.92 0.89 0.93 0.96 0.96 0.98 0.99 0.99 0.99 0.997 1 0.067 0.09 0.14 0.26 0.36 0.56 0.53 0.70 0.83 0.78 0.87 0.93 0.92 0.95 0.97 0.98 0.99 0.994

In Table 63 it is designated: ω =N

A R mn y.

Notes: 1. Intermediate values of coefficient ψ are determined by the linear interpolation. Force N shall be accepted with sign “plus”.

Table 64* Af, min / 4.33. Value of coefficient ψ at ω

Af, max -0.05 -0.2 -0.4 -0.6 -0.8 -0.95 at Af, max / Aw

0.5 1 2 0.5 1 2 0.5 1 2 0.5 1 2 0.5 1 2 0.5 1 2 0 0.9 0.9 0.9 0.6 0.6 0.6 0.2 0.2 0.2 -0.2 -0.2 -0.2 -0.6 -0.6 -0.6 -0.9 -0.9 -0.9

0.5 0.42 0.40 0.38 0.17 0.12 0.02 -0.17 -0.25 -0.32 -0.49 -0.53 -0.56 -0.76 -0.78 -0.79 -0.94 -0.94 -0.95 1 -0.07 -0.09 -0.14 -0.27 -0.36 -0.56 -0.53 -0.70 -0.83 -0.78 -0.87 -0.93 -0.92 -0.95 -0.97 -0.98 -0.99 -0.99

Notes: 1. For designation see Table 63. Force N shall be accepted with sign “minus”. 3. Intermediate values of coefficient ψ are determined by the linear interpolation.

SNiP 2.05.03-84 Page 127

DESIGN FOR STRENGTH AND CREEP OF STEEL ROPES 4.34. Strength design for steel ropes for flexible load-bearing members in cable-stayed and suspension bridges as well as for stressed members of prestressed structures shall be calculated by formula NA

R mmdh≤ 1 , (163)

where Rdh - rated resistance of ropes; m - coefficient of working mode, specified by Table 60*; m1 - coefficient of working mode, specified by Compulsory Appendix 14. Rated resistance Rdh for ropes and bundles of parallel laid high-tension wires is calculated by formula (140), but for single-stranded ropes and enclosed carrying ones - by formulae

[ ]R

PAdh

un

m=

Σγ

or R kP

Adhun

m=

Σγ

, (164)

where [Rdh] - value of breaking load of the rope as a whole, specified in the State Standard or Technical Conditions; γm - 1,6 as per Item 4.17*; ΣPum - the sum of breaking loads of all wires in the rope; k - coefficient of assembly strength of twisted rope, determined in accord with Table 65.

Table 65 Rope Coefficient k at ratio of twist

6 8 10 12 14 16 Single-stranded 0.89 0.93 0.96 0.97 0.98 0.99 Enclosed carrying 0.87 0.91 0.94 0.95 0.96 0.97

4.35. Longitudinal creeping εpl, x of twisted galvanized steel ropes with metal core, single-stranded, or enclosed carrying ones, subject to prestretching shall be calculated by formula

εσ σ

pl xun

R

Re un

,

,.

=

0 001 2

2 4

, (165)

where σ - stress in the rope caused by the force, calculated from the action of characteristic dead loads and 1/3 of characteristic live load;

- characteristic resistance of the rope;

e - base of natural logarithms. 5 Cross creeping εpl, y of ropes, mentioned in item 4.34, shall be calculated by formula

εσ σ

pl yun

R

Re un

,

..= 0 003

2 19 (166)

STABILITY DESIGN 4.36. With flat crippling of web-plate members of closed and open sections subject to central compression, compression with bending, and eccentric bending compression in plane of the greatest flexibility the design shall be calculated by the following formula NA

R my≤ ϕ , (167)

where

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ϕ - coefficient of longitudinal bending, determined in accord with Table 1*-3 of the Compulsory Appendix 15* depending on the flexibility of the member λ and reduced relative eccentricity eef; m - here and in items 4.38-4.41 - coefficient of working mode taken in accord with Table 60*. The flexibility of the member λ shall be calculated by formula

λ =lief , (168)

where lef - effective length; i - radius of section inertia relatively to the axis perpendicular to the plane of the greatest flexibility (plane of bending). Reduced relative eccentricity eef shall be calculated by formula eef = ηerel (169) where η - coefficient of influence of the section shape, determined by Compulsory Appendix 15*;

erel = eρ

- relative eccentricity of bending plane (here e - is an actual eccentricity of force N under off-

center compression, and design eccentricity under compression with bending, ρ - core distance), taken under central compression equal to zero. Design eccentricity e in bending plane under compression with bending shall be calculated by formula

eMN

= , (170)

where N, M - design values of longitudinal force and bending moment. Core distance ρ in direction of eccentricity shall be calculated by formula

ρ =WA

c , (171)

where Wc - moment of resistance of gross section, calculated for the most compressed fiber. Design values of longitudinal force N and bending moment M in the member shall be taken for one and the same combination of loads from design of system by non-deformed diagram in the assumption of steel flexible deformations. In doing so, values M shall be taken equal: for frame system members constant section - to the largest moment within the member length ; for members with one fixed and other free end - to the moment in the fixed end but not less than the moment in the section detached to the third of member length from fixing; for truss compressed chords taken the off-node load – to the largest moment within the middle third of the length of the chord panel, determined by the design of the chord as elastic continuous beam for compressed bars hinged at its ends and sections, having one axis of symmetry, matching with the plane of bending - to the moment determined by formulae of Table 66.

Table 66 Relative eccentricity, corresponding to Mmax

Design values of M at the conditional flexibility of bar

Dp4 D≥ 4 erel ≤ 3

M M M M M= = − −2 14max max( )D

M=M1

3< erel ≤ 20 M M

eM Mrel= +

−−2 2

317

( )max M Me

M Mrel= +−

−1 1

317

( )max

SNiP 2.05.03-84 Page 129

In Table 66 the following is designated: Mmax - the greatest bending moment within the bar length; M1 - the greatest bending moment within the mean third of the bar length, but not less than 0,5 of Mmax; erel - relative eccentricity, calculated by formula

eM ANWrel

c= max ;

D- conditional flexibility, calculated by formula D= λαR , where αR - coefficient taken as per Table 4* of Compulsory Appendix 15*. Note: In all cases M ≥ 0,5 Mmax For compressed bars hinged at its ends and sections, having two axes of symmetry, the design values of reduced relative eccentricities eif shall be determined in accord with Appendix 6 of SNiP II-23-81*, accepting mef equal to eef and mef1 equal to eef1, calculated by formula

eMN

AWef

c1

1= ⋅η

where M1 - the largest from bending moments, applied to hinged ends of the compressed bars of the mentioned type.

4.37. Design, in case of flat crippling of framed members of closed section which branches are connected with strips or perforated sheets under central compression, compression with bending, and off-center compression, shall be made as follows: by formula (167) - of the member as a whole in the plane of bending moment action or assumed (under central compression) bending perpendicular to the plane of strips or perforated sheets; by formula (167) with determination of the coefficient of longitudinal bending ϕ as per Table 1*-3 of Compulsory Appendix 15* depending on the reduced flexibility λef - of the member as a whole in the plane of bending moment action or assumed (under central compression) bending parallel to the plane of strips and perforated sheets; by formula (167), depending on flexibility of branches λα - of separate branches. Flexibility of branch λα shall be calculated by formula (168), taking for effective length lef the distance between welded strips (clear distance) or the distance between the center of edge bolts of adjacent strips or the distance equal to 0,8 of length of hole in perforated sheet and for i - the radius of branch section inertia relative to its own axis perpendicular to the plane of strips or perforated sheets. The reduced flexibility of the framed member λef in the plane of connecting strips and perforated sheets shall be calculated by formula λ λ λαef = +2 2 , (172) where λ - flexibility of the member in the plane of connecting strips and perforated sheets determined by formula (168); λα - branch flexibility. When calculating the section area, inertia moment, and inertia radius of the member the equivalent thickness tef will be calculated for: perforated sheets, having the width b, length l , and thickness t - by formula

tt A A

Aef =−( )

,Σ 1 (173)

where A = bl - area of the sheet before perforation formation; ΣA1 - summarized area of all perforations on the sheet surface; for connecting strips with thickness t - by formula

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tt l

lef =Σ 1 , (174)

where Σl1 - the sum of lengths of all strips of the member (along the member ); l - length of the member. Framed members composed of parts tightly connected or connected via gaskets, shall be designed as continuous ones, if the greatest distances between bolts, welded strips (clear distance) or between centers of edge bolts of adjacent strips do not exceed: for compressed members - 40i; for tensioned members - 80i; Here the inertia radius i of the angle or channel is to be taken for built-up T- or I-sections relatively to the axis parallel to the plane of gaskets location, but for cross-shaped sections - the inertia radius shall be the minimal. In doing so, not more than 2 gaskets shall be used within the length of compressed member.

4.38. Calculation at torsional-flexural buckling of web-plate members of open section, with moments of inertia Iz > Iy, subject to central compression by force N, shall be calculated by formula NA

R mc y≤ ϕ , (175)

where ϕc - coefficient of longitudinal bending determined by Table 1*-3 of Compulsory Appendix 15*, if e0 = 0 and

λ πycr

EAN

= .

4.39. Design for the torsional-flexural stability of web-plate members of closed and open sections with moments of inertia Ix > Iy, subject to compression with bending and eccentric compression in the plane of the least flexibility, coinciding with the plane of symmetry and axis y, shall be calculated by formula NA

NW

R me

cc y+ ≤ ϕ , (176)

where e - actual eccentricity of force N under eccentric compression and design eccentricity e = M/N under compression with bending; Wc - the moment of resistance of gross section, calculated for the most compressed fiber; ϕc - coefficient of longitudinal bending determined by Table 1*-3 of Compulsory Appendix 15*, if eef = 0 and

λ πy

crc

EA

NeAW

=

+

1

.

4.40. Design at torsional-flexural buckling of web-plate members with open and close sections, subject to compression with bending and eccentric compression in two planes, shall be calculated by formula NA

Nel

yNel

x R my

xc

x

yc c y+ + ≤ ϕ ,

where ey, ex - actual eccentricity by the direction of axes x and y under eccentric compression, and designed eccentricities under compression with bending; yc, xc - coordinates of the section point which is the most compressed by the joint action of Mx, My and N;

SNiP 2.05.03-84 Page 131

ϕc - coefficient of longitudinal bending determined by Table 1*-3 of Compulsory Appendix 15*, if eef = 0 and

λ π=

+ +

EA

Ne Al

ye Al

xcry

xc

x

yc1

Besides, the design calculated by formula (167) should be done with assumption of flat crippling in the plane of axis y with the eccentricity ey (if ey = 0) and in the plane of axis x with the eccentricity ex (if ey = 0).

4.41. The design at torsional-flexural buckling of web-plate beams, bent in one plane, shall be calculated by formula MW

R mc

b y≤ εϕ , (178)

where M - the greatest design bending moment within the design length lef of the compressed chord of the beam; Wc - beam section resistance moment for the edge fiber of the compressed chord; ε - coefficient calculated by formulae:

if λy < 85, then ε = 1+(∂-1)(1-λy

85);

if λy ≥ 85, then ε = 1.0; here ∂ is the coefficient calculated by formulae (143) and (144*); ϕc - coefficient of longitudinal bending determined by Table 1*-3 of Compulsory Appendix 15*, if eef = 0, and of flexibility from the web plane

λ πyc

cr

EWM

= .

4.42. The design at torsional-flexural buckling of web-plate beams bent in two planes shall be calculated by formula (178), in doing so the coefficient ϕb is taken as per Table 1*-3 of Compulsory Appendix 15*, if eef = ηerel; Here, η - coefficient taken as per Compulsory Appendix 15*; erel - relative eccentricity calculated by formula

erel = σ

σfh

fv,

where σfh - the greatest stress in the point of the side edge of the compressed chord, caused by the bending moment in the horizontal plane in the section, being within the middle third of the unfixed length of the compressed beam chord; σfv - stress in the compressed beam chord, caused by the vertical load in the same section.

4.43. Checking of general stability of simply supported beam and compressed zone of continuous beam chord shall not be carried out if compressed chord is connected with reinforced concrete or steel plate.

STABILITY DESIGN FOR FLANGES AND WEBS OF MEMBERS NOTE REINFORCED WITH STIFFENERS

4.44. Stability design of flanges and webs of rolled and composed welded centrally and eccentrically compressed members and also of compressed-flexural and flexural members of constant cross section not reinforced with stiffeners (Dwg. 11) shall be calculated by the theory of prismatic folded shells. Drawing 11. Diagrams of design sections of members not reinforced with stiffeners.

SNiP 2.05.03-84 Page 132

4.45. *Stability of flanges and webs of members not reinforced with stiffeners at the middle tangential stress, not exceeding 0.2 σx, can be provided by designation of ratio of web height (h, hw) or flange width (bρ, bh) to thickness (t, tw, tρ, th) being not more than 0.951 α / σ x cr ef E, , / (here α is a

coefficient, σx, cr, ef - reduced critical stress). The coefficient α is to be determined: by the following formula for plates with width bh, h supported at one side (Dwg.11 б-е)

;085.0405.043

10.31 2ξς

α +

+

+= (180)

by the following formula for plates with the width hw, bf supported at two sides (Dwg.11 а, б, г)

ας

ξ= ++

+1

0 9610 3

4 385 2 33.. . (181)

In formulae (180) and (181): ζ - coefficient of plate restraint, determined by formulae of Table 67; ξ - coefficient (for gross sections only) determined by formula

ξ=1-σα

x

x

−

,

where σx, σx¯ - maximal and minimal longitudinal normal stress which are positive under compression and are applied to the plate longitudinal borders and determined by formulae (141) - (158) at the loading being unfavorable for plate stability, in doing so coefficients ∂,∂x, ∂y, ψ, ψx, ψy shall be specified equal to 1.0. The reduced critical stress σx, cr, ef for the plate shall be calculated as per the formulae of Table 68* depending on critical stresses σx, cr, that shall be specified as acting stresses σx/m (here m is the coefficient of working mode taken as per Table 60*).

STABILITY DESIGN FOR FLANGES AND WEBS OF MEMBERS REINFORCED WITH STIFFENERS

4.46. Stability design for flanges and webs reinforced with stiffeners shall be carried out in accord with the theory of prismatic folded shells strengthened with cross diaphragms. Stability of plates, flanges and webs of the mentioned members can be designed in accordance with Compulsory Appendix 16*.

Table 67 Coefficient of plate restraint ζ

webs flanges - for angle section at bh/h Type of member section 1 0.667 0.5

Box section (dwg.11, a) ς β

β α1 13

12

12

0 381

=−

.

ς

ββ α

213

12

12

1 0 38

11= ⋅

−

.

I-section (dwg.11, б) ς β α

β α3 23

22

22

016 0 00561

1 9 4=

+

−

. .

.

ς

β αβ α

423

2

22

22

1 2

1 01061= ⋅

− .

T-section (dwg.11, в) ς β

β α5 33

32

23

11

=−

ςβ α

β α

633

3

32

32

1 2

11= ⋅

−

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Channel section (dwg.11, г)

ς ς7 32= ς ς8 4

12

=

Angle section for flange with the height h (dwg.11, д)

--- ζ9 = ∞

ζ9 = 10 ζ9 = 5.2

Cross-shaped section (dwg.11, e)

ζ10 = ∞ ζ10 = ∞

In Table 67 the following is designated:

β1 =tt

w

f; α1 =

bh

f

w; β2 =

tt

w

h; α2 =

bh

h

w; β3 =

tth

; α3 =bhh .

Note: 1. If the value of denominators in formulae given in Tables 67 is negative or equal to 0, then ζ = ∞. 2. The value ζ9 shall be determined by interpolation for the angle section with ratio bh/h that is not mentioned in Table 67, in so doing, for bh/h = 1 the value ζ9 shall be taken equal to 100.

Table 68* Steel Quality Values of σx, cr

MPa, (kg/cm2) Formulae for calculation σx, cr, ef or its value

MPa, (kg/cm2) 16Д up to 176 (1800) 1.111 σx, cr Ст3 more than 176 (1800) to

205 (2100) 1868 10 2 420 10 1 10003 3. . ,⋅ − ⋅ −

− −σ x cr

EE

more than 205 (2100) 385 (3923) 15ХСНД up to 186 (1900) 1.111 σx, cr

more than 186 (1900) to 284 (2900) 2 544 10 2 620 10 1 7243 3. . ,⋅ − ⋅ −

− −σ x cr

EE

more than 284 (2900) 524 (5342) 10ХСНД up to 206 (2100) 1.111 σx, cr

390-14Г2АФД more than 206 (2100) to 343 (3499) 2 868 10 2 778 10 1 6003 3. . ,⋅ − ⋅ −

− −σ x cr

EE

390-15Г2АФДпс

more than 343 (3499) 591 (6023)

4.47. *The stability of orthotropic deck plates can be provided by designation of thickness to width ratio in accord to item 4.45* , at this: for strip longitudinal ribs the coefficient shall be calculated by formula (180) when the restraint coefficient is vs and overhang of T-beam flange is bh (dwg.12, a), equal to 0.5 hw, if ρ2 th ≥ hw, or ρ2 th if ρ2 th < hw. for plate portion of orthotropic deck in between adjacent longitudinal strip ribs the coefficient α shall be calculated by formula (181) with the coefficient of restraint ζ7, height of the web hw, equal to a distance between longitudinal ribs, and the flange overhang bh, equal to height of the longitudinal rib (dwg.12, б), but not more than ζ1th; here ζ2 and ζ1 are coefficients determined according to item 4.55*. Drawing 12. Diagrams of design sections of orthotropic deck plates

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EFFECTIVE LENGTHS 4.48. Effective lengths lef of the main truss members, but with the exception of members of crossed lattice, shall be taken according to Table 69.

Table 69 Direction of longitudinal bending Effective length lef of

chords supporting diagonal braces and bearing

supports *

other members of lattice

1. In a plane of truss l l 0.8l 2. In direction perpendicular to a

plane of truss

(from plane of plane)

l1 l1 l1

In Table 69 the following is designated: l - geometrical length of the member (a distance between centers of nodes) in a plane of truss; l1 - a distance between joints fixed against displacement from a plane of truss. * Effective length of supporting diagonal braces and bearing supports nearby intermediate piers of continuous deck structures shall be taken as for the other members of the truss web.

4.49. Effective length lef of the member, that length is acted upon by different compressing forces N1 and N2 ( moreover N1 > N2), from a plane of truss (with triangular lattice with strut frame or subdiagonal lattice, etc.) shall be calculated by formula

l lNNef = +1

2

10 75 0 25( . . ), (182)

where l1 – a distance between nodes fixed against displacement from a plane of truss. In this case the stability shall be designed for force N1. The application of the formula (182) is allowed when tension force N2 is used; in this case the value N2 shall be taken with the sign “-“ , and lef ≥ 0.5 l1. 4.50. Effective lengths lef of the main truss cross lattice members shall be taken as: in a plane of truss - equal to 0.8l , where l is a distance from the center of truss node to their crossing point; from a plane of truss; for compressed members - as per Table 70; equal to the whole geometrical length of the member (lef = l1, see Table 69) - for tensioned members.

Table 70 Structure of crossing node of truss

lattice members Effective length lef from a plane of truss when

supporting member is tensioned idle compressed

Both members are continuous l 0.7l1 l1 Supporting member is discontinued and lapped over with the gusset: the member under consideration is continuous

0.7l1

l1

1.4l1

the member under consideration is discontinued and lapped over with the gusset

0.7l1 --- ---

4.51. When checking the general stability of the beam the compressed chord effective length shall be taken equal to:

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a distance between nodes of truss of longitudinal bracing - in availability of longitudinal bracing in zone of upper and bottom chords and cross bracing in sections of support; a distance between trusses of cross bracing - in availability of longitudinal bracing only in zone of tension chords, at this, trusses of cross bracing shall be centered with longitudinal bracing nodes, and chords flexibility of mentioned trusses shall not exceed 100; the beam span length - in absence of longitudinal and cross bracing in the span; a distance from the cantilever end to the nearest plane of cross bracing behind the cantilever section of support – during cantilevering or incremental launching.

4.52. The effective length lef of compressed chord of the main beam or truss of “open” deck structure without longitudinal bracing on the given chord, shall be determined from stability design of the bar on flexible supports, compressed by length- variable longitudinal force It is allowed to calculate the above mentioned effective length by formula l lef = µ , (183) where l - the length of chord, equal to the design span for beams and trusses with parallel chords, to the full length of the chord for beams with curved upper chord and trusses with polygonal upper chord. µ - effective length coefficient For chords of beams and trusses with parallel chords, and also for trusses with polygonal chords or beams with curved upper chords the effective length coefficient µ shall be determined according to Table 71, at this, the greatest displacement δ shall be taken for the frame located in the middle of the span.

Table 71 ξ Coefficient µ ξ Coefficient µ 0 0.696 150 0.268 5 0.524 200 0.246 10 0.443 300 0.225 15 0.396 500 0.204 30 0.353 1000 0.174 60 0.321 more than 1000

0.174 1000

4ξ

100 0.290 The following is designated in Table 71:

ξδ

=l

d EIm

4

16,

where d – a distance between frames, fixing the chord against cross horizontal displacements; δ - the greatest horizontal displacement of the frame node (except supporting frames) caused by force F=1 ; Im - the mean (by length of deck) value of the inertia moment of beam (truss) compressed chord relatively the vertical axis. Note: 1. If the effective length in accord with data of Table 71 lef < 1.3d, it shall be determined by the calculation of stability of the bar on the flexible supports. 2. For intermediate values ξ the coefficient µ shall be determined by the linear interpolation.

4.53. *Stability of arches is designed on computers, with allowance of collaboration of arches and members of the roadway parts and its supporting members.. When checking the general stability of arch of constant entire section it is allowed to design length lef in its plane by formula

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,8 lleff θα

π= (184)

where l - length of arch span; α = f/l - coefficient (here f is rise of the arch); θ - coefficient, taken as per Table 72. Value of θ for double-hinged arch of variable cross-section, when its inertia moment is changed within ± 10 % of the mean value of the inertia moment lengthwise the span, shall be determined in accord with item 4 of Table 72, taking EIbog in the quarter of the span. In all cases the effective length lef of the arch in its plane shall be not less than a distance between nodes fastening the supports or hangers.

Table 72 Type of arch Coefficient θ

1. Roadway two-hinged arch with flexible tie bars*, connected with the arch by hangers

θ = 2θ1

2. Fixed arch θ = 2θ1 + αθ1 3. Three-hinged arch The least among θ = θ1 and θ = θ2 4. Two-hinged arch with continuous stiffening girder, connected with the arch by supports

12

1 )7.095.0( βθαθθ ++=

The following is designated in Table 72: θ1 and θ2 - coefficients, taken as per Table 73*; α - see formula (184);

β =EIEI

bal

bog; here Ibal and Ibog are sections inertia moments of the stiffening girder and the arch,

accordingly. * If the ratio of rigidity of tie-bar and arch is more than 0.8, arch effective length is determined as for double-hinged arch with continuous stiffening girder, connected with the arch by supports.

Table 73* α Coefficients α Coefficients θ1 θ2 θ1 θ2

0.1 28.5 22.5 0.5 36.8 44.0 0.2 45.4 39.6 0.6 30.5 --- 0.3 46.5 47.3 0.8 20.0 --- 0.4 43.9 49.2 1.0 14.1 ---

Note: For intermediate values α coefficients θ1 and θ2 shall be determined by linear interpolation.

4.54. The effective length lef of members of longitudinal and cross bracing of any type of the lattice, except Cross one, shall be equal: in a plane of bracing: to the distance l2 between centers of fastening the bracing members to the main trusses or beams and to the roadway beams as well; from a plane of bracing: to the distance l3 between crossing points of the bracing member axis with the axes of edge rows of bolts for fastening the gussets bracing to the main trusses and beams and to roadway beams as well; The effective length lef of bracing Cross members shall be equal: in a plane of bracing: to the distance from the center of fastening the of bracing member to the main truss and beam and also to the beam roadway - to the crossing point of bracing axes; from a plane of bracing: for tensioned members equal to l3; for compressed members - as per Table 70, adopting for l a distance from the crossing point of the bracing member axis with the axis of

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edge row of bolts for fastening the gussets bracing, to the crossing point of bracing members axes, for l1. - a distance l3. For bracing members of any type of the lattice, excluding cross-shaped one, composed of single angles, the effective length lef shall be equal to a distance l between edge bolts of angle ends fastening. When cross lattice of bracing is used, lef is equal to 0.6l. The minimal inertia radius of sections must be adopted. (i = imin)

4.55. *In web-plate beams the effective length lef of bearing supports, consisting of one or some bearing stiffeners and web part, adjacent to them, shall be calculated by formula lef = µlc, (185) where µ - effective length coefficient; lc - the length of bearing support of the beam, equal to a distance from the top of jack beam to the upper chord or to the nearest node of cross bracing. The coefficient of effective length µ of bearing supports shall be calculated by formula

µ =++

nn

0 56014..

; (186)

here nlI

Il

c

c

r

r= ⋅ ,

where Ic - inertia moment of bearing support section relatively to the axis, coinciding with the web plane; Ir, lr - inertia moment of the section and the length of strut of cross bracing accordingly; in formula (186) n is equal to 0 for “open” span structures. When determining the area, inertia moment, and inertia radius of the bearing support having one stiffener, its section should include besides bearing stiffener the adjoining web parts with width b1 = θ1t (here t - the section thickness, θ1 - coefficient, taken according to Table 74*). Table 74*

Table 75* Steel quality Value of coefficient θ1 Steel quality Value of coefficient θ2 16Д 14 16Д 44 15ХСНД 12 15ХСНД 38 10ХСНД, 390-14Г2АФД, 390-15Г2АФДпс

11.5 10ХСНД, 390-14Г2АФД, 390-15Г2АФДпс

36

When determining the area, inertia moment, and inertia radius of the bearing support having several stiffeners, with the distance between them b2 = θ2t (here θ2 - coefficient, taken by Table 75*), its section should include all mentioned stiffeners, parts of web between them, and also outside adjoining to stiffeners of the web parts with width b1 = θ1t where θ1 shall be taken according to Table 74.

LIMIT SLENDERNESS OF BAR MEMBERS 4.56. *The slenderness of bar members shall not exceed values, given in Table 76*.

Table 76* Structure members Limit slenderness of

bar members of bridges railway and

pedestrian bridges highway and city

bridges Compressed and compressed-tensioned members of main trusses; supporting struts; tensioned members of

100 120

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main truss chords Tensioned members of main trusses, except chords; members intended for the reduction of effective length lef

150 150

Compressed members of longitudinal bracing of main trusses and longitudinal beams and also brake bracing

130 150

Tensioned members of longitudinal bracing of main trusses and longitudinal beams and also brake bracing

130 180

Members of cross bracing: on the support 130 150 in the deck 150 150 Truss chords of cross bracing in the level of which longitudinal bracing are absent, or the plate, united with main beam chords for working in collaboration

100 100

Branches of composed compressed or compressed-tensioned member

40 40

Branches of composed tensioned or compressed-tensioned member

50 50

DESIGN FOR ENDURANCE OF STEELWORK MEMBERS AND THEIR CONNECTIONS 4.57. *Endurance of steelwork members and their connections (except the ropes) shall be designed by formula

σ γmax, ;ef w yR m≤ (187) τ γmax, . ,ef w yR m≤ 0 75 (188)

where σmax, ef – the absolute greatest normal stress (tension stress is positive); τmax, ef – the absolute greatest shearing stress when fillets are designed for shear (shear direction is taken as positive one); γw - coefficient; m - coefficient of working mode, taken in accord with Table 60*. Stresses σmax, ef and τmax, ef from loads, indicated in items 2.1*-2.3, shall be calculated by formulae of Tables 77 and formulae (206) - (217), accordingly.

Table 77 State of stress Formulae for calculation of σmax, ef Tension or compression N

An

Bending in one of the main planes MWn∂3

Tension or compression with bending in one of the main planes

nn WM

AN

3∂±

Bending in two main planes M yI

M xI

x

x n

y

y n∂ ∂3 3, ,±

Tension or compression in two main planes

NA

M yI

M xIn

x

x n

y

y n± ±

∂ ∂3 3, ,

The following is designated in Table 77: M, Mx, My - reduced bending moments in section under consideration, calculated in accord with item 4.28*;

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∂3 - coefficient, equal to 1.05. Note: When calculating members with frictional connections on high-tension bolts the characteristics of gross sections are substituted into formulae of Table 77. The coefficient γw shall be calculated by formula

( ) ( )[ ] ,11≤

−±∂=

ρδαβδαβθγ

mm (189)

where θ - coefficient, equal to 1.0 for railway and pedestrian bridges, and 0.7 for highway and city ones; ∂ - coefficient that depends on the length of loading λ of influence line, when σmax is calculated; α, δ - coefficients, considering the steel quality and non-stationarity of load regime. β - effective coefficient of stress concentration, taken as per Table 1* of Compulsory Appendix 17*; ρ - coefficient of asymmetry of variable stresses cycle. Coefficient ρ shall be calculated by formulae

ρσσ

= min

max; (190)

ρττ

= min

max, (191)

where σmin,, σmax, τmin, τmax - the least and the greatest by absolute values meanings of stresses, with their own signs, calculating in the same section, by the same formulae as the σmax, ef, τmax, ef; at that, ∂3 shall be taken equal to 1.0. In the formula (189) the upper signs in parentheses shall be taken when calculating by formula (187), if σmax > 0, and any time when calculating by formula (188). Coefficients α, δ shall be taken according to Table 78*.

Table 78* Steel Quality Coefficient values

α δ 16Д 0.64 0.20 15ХСНД 0.72 0.24 10ХСНД 0.81 0.20 390-14Г2АФД, 390-15Г2АФДпс When calculating coefficients γw for welded joints the values of coefficients α and δ shall be taken the same as for the metal of the member. Coefficient ζ shall be taken equal to: if λ ≥ 22 m, then ζ = 1 (192) if λ < 22 m, then ζ = v - ξλ, (192) where values of v and ξ shall be taken as per Table 79*.

Table 79* Values of coefficients v and ξ for steel of quality Effective

coefficient of stress

concentration β

16Д 15ХСНД, 10ХСНД, 390-14Г2АФД, 390-15Г2АФДпс

v ξ v ξ 1.0 1.45 0.0205 1.65 0.0295 1.1 1.48 0.0218 1.69 0.0315 1.2 1.51 0.0232 1.74 0.0335 1.3 1.54 0.0245 1.79 0.0355 1.4 1.57 0.0258 1.83 0.0375

SNiP 2.05.03-84 Page 140

1.5 1.60 0.0271 1.87 0.0395 1.6 1.63 0.0285 7.91 0.0415 1.7 1.66 0.0298 1.96 0.0436 1.8 1.69 0.0311 2.00 0.0455 1.9 1.71 0.0325 2.04 0.0475 2.0 1.74 0.0338 2.09 0.0495 2.2 1.80 0.0364 2.18 0.0536 2.3 1.83 0.0377 2.23 0.0556 2.4 1.86 0.0390 2.27 0.0576 2.5 1.89 0.0404 2.31 0.0596 2.6 1.92 0.0417 2.36 0.0616 2.7 1.95 0.0430 2.40 0.0636 3.1 2.07 0.0483 2.57 0.0716 3.2 2.10 0.0496 2.62 0.0737 3.4 2.15 0.0523 2.71 0.0777 3.5 --- --- 2.75 0.0797 3.7 --- --- 2.84 0.0837 4.4 --- --- 3.15 0.0977

4.58. Endurance of the ropes shall be designed by formula σ γmax ,≤ m R mws dh1 (193) where m1 - coefficient of the rope working mode, when designing for the endurance, equal to: 0.83 - for flexible load-bearing members of suspension and cable-stayed bridges without individual control of force in the ropes; 1.0 - for stressed members of prestressed structures and flexible load-bearing members of suspension and cable-stayed bridges when the force is controlled individually in the ropes, and by the value of sag when rope is under erection; Rdh – rated resistance of ropes, determined as per item 4.33; γws - coefficient, considering the variability of stresses, and calculated by formula

( )[ ]γθς β β ρ

wss s

=− − −

≤015

0 884 0 387 0 884 0 4551

.. . ( . . )

, (194)

where θ, ζ,, ρ - coefficients, taken according to item 4.57*; βs - effective coefficient of stress concentration, values thereof are taken according to Table 2 of Compulsory Appendix 17*; m - coefficient of working mode, taken according to Table 60*.

SPECIAL FEATURES OF DESIGN OF LOAD-BEARING MEMBERS AND CONNECTIONS MEMBERS OF MAIN TRUSSES

4.59. Members and connections of lattice main truss with ratio of section depth to member length above 1/15 should be designed for strength taking into consideration the bending moments of nodes rigidity. This requirement is also refer to endurance designs of lattice main truss members with nodal connections on high-tension bolts; in case of welded node connections the endurance shall be designed with allowance of bending moments of nodes rigidity independently on the value of section depth-to-member length ratio. Strength of lattice main trusses, having roadway level chord that works for combined action of axial forces and bending from out-of-node load application, shall be designed taking into consideration rigidity of nodes of mentioned chord ignoring the ratio of section depth to panel length. Rigidity of other nodes shall be taken into consideration as indicated above.

SNiP 2.05.03-84 Page 141

In all above mentioned cases bending moments of nodes rigidity shall be reduced by 20 % in all strength designs. Bending moments of bracing contiguity or horizontal diaphragms with eccentricity and of incomplete (with allowance for item 4.22*) centering of truss members shall be included completely. This requirements is also applied to bending moments appeared in horizontal and inclined members of lattice main trusses and bracing of their dead weight. At this, these bending moments can be considered as distributed over a parabola with ordinates in the middle of member length and at the ends thereof equal to 0.6 of the moment for the freely supported member.

4.60. *In the design for stability of lattice main truss members it is allowed not to consider bending moments caused by nodes rigidity, action of bracing and transverse beams. Lattice truss members, having closed box section with the ratio of side dimensions not exceeding 2, can be designed for stability by plane bent forms relatively horizontal and vertical axes of section.

4.61. Bearing supports, struts, tie rods, bracing and other members of span structure used to decrease free length of compressed members, shall be designed for compression and tension with weight equal to 3 % of longitudinal force in compressed member.

4.62. In arch bridges with transmission of thrust to piers the longitudinal bracing between arches shall be designed as members of the fully fixed truss. In simple beam span structures the wind truss formed with chords of main trusses and longitudinal bracing is taken as simple beam truss, movable-supported in its plane at portals or bearing parts. In arches and with polygonal outline of truss chords the forces in the wind truss chords can be determined as for the plane truss, dividing the obtained results by cosine of inclination angle of the given member to the horizontal. In continuous through span structures the wind trusses formed with main trusses chords and longitudinal bracing, shall be designed as continuous beam span structures, assuming the upper truss as movable-supported at elastic supports -. portals onto the terminal supports, and onto each intermediate support of main trusses, and assuming the lower truss as being supported onto the rigid supports - . bearing parts.

4.63. Main trusses and bracing members can be not designed for bending against wind impact. Supporting portals shall be designed for reaction action of the corresponding wind truss, at this, horizontal components of longitudinal forces in the legs of inclined supporting portals shall be considered in the lower chords of beam span structures.

4.64. Chords of main trusses and lattice members, adjacent to the bearing node, shall be designed for the axial force and bending moment from the longitudinal braking force or traction force, which are transferred with the eccentricity to the fixed bearing part; as well as for bending moment from eccentricity of reaction of single-roller bearing part relative to the center of the bearing node. Distribution of bending moments between members of the bearing node shall be taken as per item 4.22.

4.65. Transverse reinforcing members, formed by lattice or web-plate diaphragms in the decks of box and П-shaped sections as well as transverse ribs and sheets of orthotropic plates and beam webs, shall be checked for strength, stability and force endurance, determined, as a rule, by the spatial analysis of decks. It is allowed to design transverse reinforcing elements as frames or beams, configuration thereof corresponds to the cross beam of the deck, and the section includes, together with transverse ribs and diaphragms, latticed or web-plate, the sheet with total width of 0.2 of the distance between adjacent webs of main beams, but not exceeding the distance between transverse reinforcing members. Transverse reinforcing members in sections of support have rigid supports in the place of bearing parts position. These reinforcing members are to be designed for the bearing reactions, local

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vertical load and tangential stresses caused by bending and torque of spans, adjacent to the given deck support, and distributed over the contour of cross section in the sheets of webs and orthotropic plates. Transverse reinforcing members located in the span, and also in the place of concentrated force (for example, forces due to the back stays) application, shall be designed, taking into consideration all external forces and tangential stresses due to bending and torsion in the sheets of webs and orthotropic plates.

4.66. In design for the strength and endurance of linear railway span structures, located on the curve sections, having radius less than 1000 m, forces, appearing when the span structure is under the torsion as a spatial one, shall be considered.

4.67. In case of multistage construction of a structure the strength of sections on the intermediate stages of construction shall be checked by formula (141)-(158), adopting coefficients ∂,∂x, ∂y, Ψ, Ψx, Ψy as equal to 1.0. 4.68. Longitudinal deformations of back stays of span structures of cable-stayed bridges shall be determined, taking the reduced modulus of elasticity, calculated by formula

EE

E g l A S SS S

ef = −+ ⋅

+1

24

2 2 2 31 2

12

22

ρ, (195)

where E - modulus of elasticity of the rope, determined by Tables 58* and 59; ρ - density of rope material; g - acceleration of gravity; A - area of cross section of rope; S1, S2 - initial and final values of force in the back stay accordingly, before and after the load application, calculation is made for. Forces in back stays shall be determined by successive approximation.

4.69. Towers of cable-stayed and suspension bridges must be checked for strength and stability on the basis of deformation calculations. Flexibility of the tower, while checking general stability, shall be determined accounting for the variable of stiffness, conditions of its fixing and loading on piers and in the nodes of connection of cross bars, cables and back stays. For single-column towers of cable-stayed-beam bridge the tracing effect due to the forces in back stays shall be considered.

4.70. Structures with prestress or regulation shall be checked by the design for strength and stability on all stages of application of prestress or carrying out of regulation, at that, working mode coefficient shall be taken as per item 4.19*, load reliability coefficient (more or less 1,0) shall be taken as per Section 2, and stresses calculated for each stage shall be summarized. When calculations are made the losses of stresses due to relaxation, friction and anchors pliability of stressed members shall be considered in accord with the Compulsory Appendix 11*.

MEMBERS OF BRIDGE ROADWAY 4.71. *Bridge deck stringers of decks without rupture of stringers (or without special nodes with longitudinally-movable bearing of their ends, adjoining to each other), shall be designed by strength, by flexible stage of work, taking into consideration additional forces due to their collaboration with chords of main trusses, in so doing, the decrease of forces in main trusses chords is allowed to be considered only when bridge roadway is involved into collaboration with them by means of special horizontal diaphragms.

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4.72. When bridge roadway is involved into the collaboration with lattice main trusses the decrease of forces in the main trusses chords is to be considered only in respect to the impact of live vertical load in calculations of all bolt-welded decks independently on the sequence of the erection thereof. The deformation of chords shall be considered as follows when determining forces in the bridge roadway: due to the all kinds of load - when the bridge roadway is involved into collaboration with the main trusses simultaneously with erection thereof; due to the live vertical load - when the bridge roadway is collaborated with main trusses after transmission of dead load to the main trusses.

4.73. Forces in the bridge roadway members due to their collaboration with main trusses shall be determined, assuming that the following types of fastening exist in the horizontal plane: hinge connection of cross beams to longitudinal ones; the cross beam chord, positioned in the level of bracings, is connected rigidly to the chords of main trusses, but another chord thereof has a hinge connection. Design for section strength of cross beams considering bending moments My in the horizontal plane, occurring when bridge roadway members collaborate with main trusses chords, shall be calculated by formulae (146) - (150), adopting My as being reduced by 20 %. In design for strength of bridge roadway members with plated ballastless bridge floor it is necessary to account for forces, appearing in members due to the involving of plates into the collaboration with longitudinal beams.

4.74. Forces in longitudinal beams with fishplates on the upper or on the both chords in conjugation with cross beams shall be calculated, taking into consideration the continuity of beams and elastic compliance of supports. The distribution of the axial force and bending moment in between fixings of chords and webs of longitudinal beams shall be made, considering their compliance.

4.75. Longitudinal beams of latticed decks with the bridge roadway, not collaborated with main trusses, are allowed, independently on the structural design of fixing of main trusses chords, adjoining to the cross beams, to be calculated for the strength as simple supported ones, at that, members of chords and beam webs fixing to the cross beams shall be calculated by 0,6 of moment in the middle of simple supported beam center with the distribution of moment as per item 4.74. Bending moments shall be determined by lines of influence of simple supported beam upon the elastic yielding supports when mentioned longitudinal beams are designed for the endurance.

4.76. *Cross beams of latticed decks shall be designed as members of frames, formed by the cross beam and main trusses members, adjoining to the hitch plates. Section of support of cross beams, hangers, supports (also web diagonal of main trusses if hangers and supports are not employed) shall be checked for bending moments, appearing in members of frame, formed by the above mentioned members due to the bending of cross beams, being under vertical load. Bending moments in members of closed transverse frames for the single-track span structures of railway bridges are allowed to be calculated by the formulae: support bending moment in the cross beam

MFa B a

B HB

I

I IGE

Hl

stbal

c tm

=−

⋅+ ⋅

+ ⋅

( );

1

12

2

(196)*

bending moment in a hanger or support: at the edge of cross beam fastening

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M MIc

I IGE

Hl

c st

c tm

=+ ⋅

2

; (197)

in the level of center of cross bracings node nearest to the cross beam, but if there are no cross bracings - in the level of center of opposite chord of the main truss M Mci c= −05. . (198)

In formulae (196)* and (197): F - support reaction of cross beam; a - distance in between axis of section of main truss chord and axis of section of longitudinal beam; B - distance in between axes of main trusses chords; lm - length of main truss panel (distance in between cross beams); H - effective length of a hanger of support out of the truss plane; Ibal - inertia moment of gross section of cross beam in the mid length thereof; Ic - moment of inertia of gross section of a hanger or support in respect of axis parallel of to the plane of main truss; It - moment of inertia of simple torsion of truss chord, adjoining to the cross beam.

4.77. In through span structures of open type cross frames shall be designed for conventional lateral forces, applied on the level of center of gravity of truss section and equaled to 2 % of longitudinal force in compressed chord of the beam or truss.

4.78. Forces in the members of bridge deck with steel orthotropic plates of motorway, urban, combined and pedestrian bridges shall be determined, using spatial structural models with discontinuous arrangement of cross ribs and considering the collaboration of plates with main trusses (beams). Strength design of the orthotropic plate members shall be executed according to the Compulsory Appendix 18*, but endurance design - to the special method.

MEMEBERS OF BRACING 4.79. *Forces in members of longitudinal bracings with crest-shaped, rhombic-shaped and triangular-shaped lattice, appeared due to the deformation of chords of main trusses or beams, shall be determined by the vertical load, which acts after they have been involved to the joint action. Forces in members of longitudinal bracings, not connected with longitudinal beams or connected with them if gaps in bracings are available (see Item 4.71*) are allowed to be calculated by formulae: in the diagonal of crest-shaped lattice when cross bent beam acts as a bracings thrust. N Ad d f mf= +( cos sin );σ α σ α2 2 (199) in other diagonals of crest-shaped lattice

NAAA

df d

d

c

=+

σ α

α

cos

sin;

2

31 2 (200)*

in the diagonal of rhombic-shaped lattice

NA

AA

AI

Bd

f d

d

c

d=

+ +

σ α

α α

cos

sin cos;

2

3 2 31 248

(201)

in the diagonal of triangular-shaped lattice

NA

AA

AI

Bd

f d

d

c

d=

+ +

σ α

α α

cos

sin cos;

2

3 2 31 212

(202)

SNiP 2.05.03-84 Page 145

in bracings thrust with any type of lattice N N Nc d lin d rec= +( ) sin. . α (203) In formulae (199)-(203): Nd, Nc - forces in the diagonal and thrust accordingly; Nd.lin, Nd.rec - forces in the diagonal from the left and the right sides of the thrust accordingly; σf - normal stress in the main truss chord; σmf - average stresses in the lower chord of cross beam (calculated considering ununiformity of distribution of bending moments over the beam length); Ad, Ac - area of section of diagonal and thrust of bracings accordingly; when the cross bent beam acts as a thrust, then in formula (199)-(202) Ac = ∞. I - moment of inertia of main truss chord relative to the vertical axis α - angle in between bracings diagonal and main truss chord. In formulae (199)-(202) when determining forces in bracings elements of beams with continuous web the stress σw in the web of the main beam shall be taken instead of σf, and which is calculated by the area of gross section on the level of bracings plane location; in formula (199) the average stress σmw in the web of cross beam on the level of bracings plane location and calculated in the same manner as σmf, shall be taken instead of σmf. Forces due to the vertical load in members of longitudinal bracings with semi-diagonal lattice can be ignored.

4.80. Reduction of forces in the chords of main trusses caused by involving of longitudinal bracings to the collaboration in all-welded decks shall be considered due to the total load, but in bolt-welded decks - only due to the live vertical load.

4.81. Design for the strength and endurance of main trusses chords with rhombic-shaped and triangular-shaped lattice of bracings and also with crest-shaped lattice with thrust, having different stiffness, shall be done taking into account bending moments appeared in chords due to the deformation of bracings elements and due to the deformation of bridge deck cross beams independently on the type of bracings. Bending moments in chords, acting in the plane of bracings with triangular-shaped and rhombic-shaped lattice, shall be calculated by formula

MN l

fc m=4

, (204)

where Nc - force in the bracings thrust; lm - distance in between the centers of nodes of member fixing to the chord.

DESIGN OF CONNECTIONS 4.82. *Welded, frictional and bolt connections must be designed for transmission of all forces, acting in a structure member, at that, as a rule, each part of member section (taking into consideration its weakening) shall be fastened according to the force, applied to it. When this requirement can not be met, the overloading of some zones and fastening elements shall be considered by the introduction of working mode coefficient, mentioned in Items 60* and 82. When designing element fastening to the node with the single joint plate, it is allowed to ignore bending moments in the plane perpendicular to the plane of joint plate. Distribution of longitudinal force, passing through the center of gravity of the connection, shall be taken as being uniform between bolts and weld joints of fastening. At the designing of riveted decks reconstruction the design of riveted connection shall be made in accord with instructions of “Technical Requirements for Design of Railroad, Motor Road and Urban Bridges and Pipes” (СН (Constructional Norms) 200-62).

SNiP 2.05.03-84 Page 146

Bolt connections with bolts made of steel of 40X Quality are not allowed to be used in structures designed for endurance.

4.83. *Designed depth of weld joints section shall be adopted: for butt joints: of details welded with full penetration,- tw = tmin; of details welded with incomplete penetration,- tw = tw, min; for fillets: by the joint metal - tf = βfkf; by the metal of fusion zone - tz = βzkf, where tmin - the least thickness of members to be welded; tw, min - the least thickness of butt joint section when members are welded with incomplete penetration; kf - the least of fillet leg; βf, βz - coefficients of reference sections of fillets, taken as per Table 80*.

Table 80* Coefficients of fillet reference sections

at the joint leg kf, mm Type of welding at the

diameter of welding cable d, mm

Joint position

designation 3-8 9-12 14-16 18 and more Automatic welding, d=3-5 gravity fillet weld βf 1.1 0.7 βz 1,15 1,0 underhand βf 1,1 0,9 0,7 βz 1,15 1,05 1,0 Automatic and hand gravity fillet weld βf 0.9 0.8 0.7 welding, d=1,4-2 βz 1.05 1.0 underhand, vertical, βf 0.9 0.8 0.7 horizontal βz 1.05 1.0 Hand welding with cable of continuous section at

gravity fillet weld, down- hand, vertical

βf 0.7

d<1.4 or with flux-cored electrode

horizontal, overhead

βz 1.0

Note: Coefficients values correspond to welding conditions, provided by “Instruction on the Technology of Machine and Hand Welding for Prefabrication of Steel Bridge Structures” (Mintransstroy, 1980)

4.84. Design for strength of welded butt joints shall be made: at the welding of elements with different strength degree, and also at the welding with materials for which Rwy<Ry (in this case Ry shall be indicated in designing documents); in case of moulding or weakening in the butt zone, when

lw < b or

tw, min < t; Aw, n < A,

where lw - full length of butt joint; b, t - width and thickness of butt-jointed members; Aw, n - net area of weakened (for example with holes) section of butt joint; A - gross area (or net one) of section of members to be butt-jointed in the zone of butt weld.

4.85. In case of central tension or compression design for strength of butt welds shall be calculated by formula

SNiP 2.05.03-84 Page 147

Nt l

R mw w

wy≤ , (205)

where m - coefficient of working mode, taken by Table 60*. Design calculations on strength of butt welds in case if bending in one or two main planes, and also calculations of the action of axial force with bending in one or two main planes shall be calculated by formulae (142) - (158), where geometrical parameters and coefficients ∂, ∂x, ∂y, ψ, ψx, ψy are to be calculated for sections of a butt weld, adopted according to the item 4.84, but in the right part Rym and Rsm must be substituted with Rwym and Rwsm. 4.86. The strength of weld joints with fillets under the action of transverse and longitudinal forces shall be tested for shear (conventional one) by two sections (Dwg. 13): by joint metal (section 0-1)

τ = ≤N

t lR m

f wwf ; (206)

by metal of fusion zone (section 0-2)

τ = ≤N

t lR m

z wwz , (207)

where lw - total joint length; tf, tz - design depth of joint section; m - working mode coefficient, accepted in accord with Table 60*. Drawing 13. Diagram of design sections of

fillet weld under design calculations for shear

4.87. Design calculation for strength of weld joints with fillets under the action of the moment in the plane perpendicular to the plane of joint position shall be calculated for two sections by formulae:

by joint metal

τ = ≤M

WR m

fwf ; (208)

by metal of fusion zone

τ = ≤MW

R mz

wz ; (209)

In formulae (208) and (209): Wf - moment of resistance of design section by joint metal; Wz - ditto by metal of fusion zone.

4.88. Design calculation for strength of weld joints with fillet under the action of the moment in the plane of joint position shall be made for two sections by formulae: by joint metal

τ =+

+ ≤M

I Ix y R m

fx fywf

2 2 ; (210)

by metal of fusion zone

τ =+

+ ≤M

I Ix y R m

zx zywz

2 2 ; (211)

where Ifx, Ify - inertia moment of design section by joint metal relatively to its main axes;

SNiP 2.05.03-84 Page 148

Izx, Izy - ditto, by metal of fusion zone; x, y - coordinates of the joint point, mostly distanced from the center of gravity of design joint section relatively to the main axes of this section.

4.89. The strength of weld butt joints under the simultaneous action in the same section of normal and tangential stresses shall be checked by formula (161), where σx = σwx and σy = σwy - normal stresses in the weld joint in two mutually perpendicular directions; τxy = τwxy - tangential stresses in weld joint; Ry = Rwy.

4.90. When design calculation of weld joints with fillets under simultaneous action of cross and longitudinal forces and the moment is made, the following conditions must be observed: τf ≤ Rwfm; (212) τz ≤ Rwzm; (213) where τf, τz - stresses in the design section by joint metal and by metal of fusion zone accordingly, equal to geometrical sums of stresses, caused by cross and transverse forces and the moment.

4.91. Design calculation for strength of fillets weld in places of fixing of chords sheets between each other and to the web of bent beam shall be calculated by formulae: when localized pressure is unavailable: by joint metal

τ = ≤QS

nt IR m

fwf ; (214)

by metal of fusion zone:

τ = ≤QSnt I

R mz

wz ; (215)

where n - number of fillets; when chord is influenced by localized pressure: by joint metal:

τ =

+ ≤

1 22

ntQSI

q R mf

wf ; (216)

by metal of fusion zone:

τ =

+ ≤

1 22

ntQSI

q R mz

wz ; (217)

where q - pressure due to movable vertical load, determined according to items 2.11 - 2.13 and Compulsory Appendix 5*.

4.92. Weld joints, connecting separate sheet articles of section of composite web- plate compressed members, shall be designed for the conventional transverse force, taken as being constant through the total length of the member, and determined by formula:

QWl

R Rfic yn y= −π

ϕ( ), (218)

where W - moment of resistance of gross section of member in the tested plane (weakening of sheet articles by perforation can be ignored); l - length of composite member; ϕ - coefficient of longitudinal bending when design calculation for member strength in tested plane is made. The same weld joints in compressed-bent composite members shall be designed for transverse force Ql equal to the sum of transverse forces - conventional force Qfic, determined by formula (218) and actual one.

SNiP 2.05.03-84 Page 149

If there are two or more sheet articles positioned in parallel in the section of composite member, fixing of each of them shall be designed for transverse force Qi, determined by formula

Q Qt

ti l

i

l

n

i

=∑

, (219)

where ti - thickness of sheet article to be fixed; n - number of sheet articles positioned in parallel.

4.93. When composite web-plate members are fixed to nodes of main trusses, separate parts of section thereof are not fixed indirectly to the hitch plate, weld joints of connection of unfixed part of section to the fixed one shall be designed for the transmission of force, applied to it, taking the coefficients of working mode m as equal to: m = 0,8 - when the ratio of fixed section part area Av to the total area of member section A, being less than 0,6; m = 0,9 - when the ratio Av/A is more than 0,6 up to 0,8; m = 1,0 - when the ratio Av/A is more than 0,8. In so doing, design length of weld joint shall be equal to the length of member overlapping by the hitch plate of truss.

4.94. Design force Nb, which can be taken up by a single bolt, shall be determined by formulae: for shear N R m Anb bs bl s= ; (220) for collapse N R m d tb bp bl= Σ ; (211) for tension N R Ab bt bn= , (222) where Rbs, Rbp, Rbt - design resistance of bolt connections; d - diameter of bolt shank;

Ad

=π 2

4- area of bolt shank section;

Abn - area of bolt net section; for bolts having metric thread the values of Abn shall be taken as per GOST 22356-77*; Σt - the least summarized thickness of members, collapsed in one direction; ns - number of design shear of one bolt; mbl - coefficient of working mode of connections, which is taken as per Table 81.

Table 81 Characteristics of connection Coefficient of working mode of

connection mbl Multibolt connection in the design calculations for shear and collapse when bolts are: of pinpoint accuracy of normal and rough accuracy

1,0 0,9

4.95. The number n of bolts in the connection under the action of transverse force N, passing through the center of gravity of the connection, shall be determined by formula where

Nb,min – the smallest among values of design force for one bolt, calculated by formulae (220) and (221). m, mb – coefficients of working mode, taken in accordance with Tables 60* and 82.

)233(,min,bb Nmm

Nn ≥

SNiP 2.05.03-84 Page 150

Table 82 Characteristics of butt or fixing Coefficients of working mode mh of bolts

Butt of a member or its branch, all parts of section thereof are overlapped with unilateral strap

0,9

Butt of a member or its branch with bilateral if there is a part of section, not overlapped directly

0,9

Fixing of a member in the node by the single junction plate

0,9

Fixing of the section part through: one sheet two sheets and more strap, fastened outside of connection by not less than 1/4 of the full force, which can be taken up by the strap section

0,9 0,8 0,9

Fixings by angle short plates projecting leg of channel, angle or horizontal sheet of box section

0,7

4.96. If bending moments acts in the plane of connection, distribution of forces over the bolts shall be taken proportionally to the distances from the center of gravity to the bolt under consideration.

4.97. Bolts, working in shear due to the simultaneous action of longitudinal force and moment, shall be checked for the force, determined as resultant of forces defined separately of longitudinal force and moment.

4.98. Bolts, working simultaneously in shear and tension, are allowed to be checked either for shear or tension.

4.99. Bolts for connection of webs and chords of a beam shall be designed by formulae: when localized pressure is unavailable

when chord is influenced by localized pressure q

where α - spacing of chord bolts; Nb,min – the least of values of design force for one bolt, determined according to the item 4.94; S – static gross moment of beam relatively to the neutral axis; m – coefficient of working mode, determined according to Table 60*.

4.100. Design force Qbh, which can be taken up by each surface of friction of connected members, tightened up with one high-tension bolt (with one bolt contact), shall be determined by formula

where P – tension strength of high-tension bolt; µ - friction coefficient, taken according with Table 57*; γbh – reliability index, taken according to Table 83*;

)224(;min, mNI

QSa b≤

)225(,min,2

2

mNqI

QSa b≤+

)226(,bh

bhPQγ

µ=

SNiP 2.05.03-84 Page 151

Table 83*

Values of reliability index γbh during contact surface* treatment by Number of high-tension

bolts in connection

Sandblasting and shot-blasting

Shot-blasting with application of frictional

ground or adhesive-frictional coating

Flame treatment

Steel brushes

Shot-throwing

Shot-throwing with flame heating of

metal surface in the zone of hole up to

250-300°C 2-4 1.568 1.250 1.956 2.514 1.441 1.396 5-19 1.362 1.157 1.576 1.848 1.321 1.290 20 1.184 1.068 1.291 1.411 1.208 1.189

* The number of treated contact surfaces (one of two) shall be taken as per Table 57*. The tension strength P of high-tension bolt shall be determined by formula: P = RbhAbnmbh; (227) where Rbh – design resistance to the tension of high-tension bolt, calculated by formula (139); mbh - coefficient of working mode of high-tension bolt when they are tensioned by torque equal to 0,95.

4.101. The number n of high-tension bolts in the connection under the action of transverse force N, passing through the center of gravity, shall be determined by formula

where m – coefficient of working mode, taken as per Table 60*; Qbh – design force for one bolt contact, calculated by formula (226); ns - the number of contact in the connection.

4.102. If bending moment or transverse force with bending moment acts in the plane of connection the force, applied to the high-tension bolt under consideration, shall be defined by as per requirement of items 4.96 and 4.97.

4.103. High-tension bolts, connecting webs and chords of composite beams, shall be calculated by formula: when localized pressure is unavailable

when chord is influenced by localized pressure q

where ns – number of contact in the connection; Qbh – design force, taken up by one bolt contact and calculated by formula (226); the rest symbols are the same as in item 4.99.

4.104. In case of collaboration of carriageway and chords of main trusses is provided for by special horizontal diaphragms, calculations of fixing of longitudinal beams to cross ones shall be carried out for cross force and moment taking into consideration requirements of item 4.74; in this case cross forces in bolts, connecting vertical angles to the web of vertical beam, shall be determined as for flanged joints.

)228(,sbhnmQ

Nn ≥

)229(;mQnI

QSa bhs≤

)230(,22

mQnqI

QSa bhs≤+

SNiP 2.05.03-84 Page 152

Design calculation for bolt and frictional connections of fixings of floor girder of decks with lattice main trusses are be done only for cross force, introducing additional coefficient of working mode mb according to Table 84.

4.105. Design calculation of tensioned members cover plates of trusses and chords of continuous beam shall be done with introduction of working mode coefficient m = 0,9 for cover plates.

Table 84 Characteristics of fixings and location of bolts

Features of node structure Coefficient of working mode mb

In all decks Vertical angles of fixing of cross beam to the lattice main truss node: bolts positioned in the leg of angle, fixed to the truss

Structure is not able to take up bearing moment Structure is able to take up bearing moment Independently of structure

0.85 0.9 0.9

Collaboration of floor girder and main trusses chords is not provided Vertical angles of fixing of cross beam to the lattice main truss node: bolts positioned in the leg of angle, fixed to the cross beam ditto, to the longitudinal beam

Structure is not able to take up bearing moment Structure is able to take up bearing moment Independently of structure

0.7 0.9 0.9

4.106. Sheets of hitch plates shall be checked for the strength of tensioned and compressed members fixing by counter, connecting hole centers of periphery bolts, that fasten mentioned members, by the following formula.

where N – longitudinal force in the member; t - thickness of hitch plate; m – coefficient of working mode, taken according to Table 60*; li – length of section i of hitch plate counter under checking; αi – angle contained by direction of section i of counter under checking and member axis (0 ≤ αi ≤ π/2), radian.

4.107. Strength of nodal hinge bolts is allowed to be checked in the assumption that a bolt works for bending as a freely supported beam, loaded with concentrated forces by the axis of faggot, contacted with the bolt, taking design resistance according to Table 48.

DESIGN CALCULATION OF CONNECTING STRIPS AND PERFORATED SHEETS 4.108. *Connecting strips and perforated sheets of through compressed members shall be calculated for the conventional transverse force Qfic, accepted as being constant throughout the whole length of bar and calculated by formula

where N - longitudinal force of compression of the member;

)231(,)1212,0(675,0 iiy lmtRN +Σ≤ α

)232(,ϕ

αNQ fic =

SNiP 2.05.03-84 Page 153

ϕ - coefficient of longitudinal bending when stability of the member is checked in the plane of connecting strips or perforated sheets, taken according to Tables 1-3 of Compulsory Appendix 15* dependently on the reduced relative eccentricity eef; α - coefficient, equal to 0,024-0,00007λ, but not more than 0,015, 0,017 and 0,018 for steel quality 16Д, 15ХСНД, 10ХХСНД, 390-14Г2АФД, 390-15Г2АФДпс accordingly; here λ - flexibility of the member in the plane of connecting strips and perforated sheets. Connecting strips and perforated sheets of through compressed-bent members shall be calculated for transverse force, equal to the sum of actual transverse force due to bending and conventional Qfic, calculated by formula (232). If connection members are located in several parallel planes, perpendicular to the axis, relatively thereof the stability is checked, the transverse force Q shall be distributed: over all planes of strips and perforated sheets in equal parts – in case of connecting strips and perforated sheets and their combination; over continuous sheet (faggot) to take up a part of transverse force, equal to Qbl and calculated by the following formula – in case of continuous sheet (faggot) and connecting strips and perforated sheets:

where Aef – area of gross section of through member, equal to Σbt; here b and tef are calculated according to item 4.37; Abl,ef – a part of member section, collaborating together with continuous sheet, and equal to Abl + 2tvζ1 (here Abl – section area of continuous sheet; tv – thickness of vertical sheet or faggot; ζ1 – coefficient, taken according to item 4.55*). Connecting strips and perforated sheets in the gaps in between perforated holes shall be designed for a part of transverse force Q applied thereon as members of trusses without diagonals.

DESIGN CALCULATION OF BEARING PARTS 4.109. *As a rule, members of bearing parts (rollers, rockers, plates) shall be designed as structures on the flexible base. It is allowed to calculate the force in the upper rockers of all bearing parts, but in lower rockers of unmovable bearing parts the force shall be calculated in the assumption that the load is uniformly distributed over the bearing area.

4.110. *When designing bearing parts the requirements of items 2.20* and 2.28* shall be taken into consideration, but for movable bearing parts eccentricities of pressure transmission shall be also taken into account, which are equal to longitudinal movements of rollers, sectors and rockers due to proof load and influence. Design calculation of longitudinal movements of movable bearing parts due to dead loads, live vertical load with dynamic coefficient, deformation of supports and foundations thereof and also temperature, mentioned in item 2.27*, shall be done. In so doing, impact, caused by loads, that occur due to the difference of temperature of main trusses chords equal to 15°C, on the unmovable bearing parts shall be taken into consideration, if decks have distance in between trusses-to-deck ratio equal to 1:15.

4.111. Sealing of anchor bolts shall be calculated in accordance with requirements of item 5.14 of SNiP 2.03.01-84*, introducing coefficient of working mode m equal to 0,7.

4.112. *Design calculation of deformation (in case of central angle of surface contact, equal to 90° or more) in the cylindrical hinges (journal) shall be made by formula

)233(,,

ef

efblbl A

AQQ =

SNiP 2.05.03-84 Page 154

Design calculation of diametrical compression of rollers shall be made by formula In formulae (234) and (235)*:

F – pressure on the bearing part; F1 – pressure on the mostly loaded roller; r - curvature radius of roller or hinge surface; l – length of roller of hinge; m – coefficient of working mode, taken according to Table 60*; Rlp, Rcd – design resistance to the localized deformation at the tight contact and to diametrical compression of rollers at the free contact, taken as per requirements of item 4.7*, accordingly.

DESIGNING GENERAL PROVISIONS

4.113. *When steelwork designing is carried out the following is necessary: to consider ability of technological and crane equipment of steelwork manufacturing plants and also lifting-and-conveying machines and erection facilities of construction companies; to divide the structure into the members for shipment basing on the condition that maximal work volume is done at the plant, and taking into account lifting capacity and clearance of transport facilities; to provide for fixing ties, ensuring stability and spatial unchanging of whole structure, its parts and elements during transportation, erection and operation; to carry out unification of assembly blocks, members and units as well as location of bolt holes; to ensure convenience of assembly and execution of assembly connections, providing erection fastenings of members, arrangement of assembly tables, etc.; to carry out unification of rolled stock according to shapes and lengths taking into consideration requirements on utilization of metal with minimal waste and losses; to consider rolled stock and prefabrication tolerances; to provide for the using of automatic submerged arc welding and frictional connections on high-tension bolts.

4.114. When steelwork is designed the following should be excluded: tight location of members to be welded, sharp changes of sections, occurrence of structural “notches” such as break of gussets and stiffeners or occurrence of cuts-out in them, adjoining to the surface of stressed parts of section (chords and webs of a beam, sheets of composite members, etc.) at the right angle. In order to increase endurance and cold resistance of structure and decrease of negative impacts of residual deformations and stresses, caused by welding, it is necessary to provide structural and technological measures (optimal order of member assembly and welding; weld with gradually cooling; preliminary curve and local heating; heating up of separate zones after welding; full penetration and moulding at the ends of members to be ruptured, adjoining tangentially the surface of the rest section part; mechanical treatment of stress concentration zones, etc.). In structures of Northern version the break of separate parts of section along the length of a member in whole (or erection block if frictional connections are used in butt joints of blocks) shall be excluded. Rust protection for structures, intended to be operated in tropical climate, shall be designed in conformity with GOST 9.401-91.

)234(.25,1

mRrl

Flp≤

*)235(.2

1 mRrl

Fcd≤

SNiP 2.05.03-84 Page 155

4.115. In railway bridges span structures with separate beams and bridge deck stringers must have longitudinal bracing by lower and upper chords. In railway bridges the fastening of longitudinal bracing to the webs of beams is not allowed. “Open-type” span structures (see item 4.52) and “open-type” bridge deck in railway bridges are allowed if feasibility study is done and under condition that free chords are fastened by rigid frames in the planes of cross beams, but in the bridge deck they are to be fastened by longitudinal bracing. In case of rigid bracing of beams and trusses chords (i.e. reinforced concrete or steel plate) it is allowed not to arrange longitudinal bracing in the correspondence plane, if it’s not required by the conditions of erection. In arch span structures the longitudinal bracing shall be arranged in the plane of one of the arch chords and in the plane of the bridge deck, if the plate is not used; in case of lattice arches the cross bracing shall be provided in between them and longitudinal bracing shall be provided on both chords.

4.116. Longitudinal bracing shall be centered in plan with the chords of main trusses, at that, eccentricities in the fastening from the bracing plane must be minimal.

4.117. If bridge deck of railway bridge has sleepers, then distance in between axes of longitudinal beams shall be 1.90 m, but in between axes of main beams (trusses) if there is no beam grid it must be 2.00 m. Reinforced concrete or steel plate shall be arranged, when the distance in between the axes of main beams (trusses) is more.

4.118. In railway bridges span structures with separate I-beams longitudinal beams of bridge roadway must have cross bracing, located at the distance, not exceeding two heights of beams.

4.119. In order to decrease stresses due to the deformation of main trusses chords in the cross beams of bridge deck, as a rule, the bridge roadway is to be involved into collaboration with main trusses. In spans with bridge roadway, not involved into collaboration with main trusses, brake bracing shall be arranged.

4.120. Fastening of bridge roadway beams with the help of end blocks, welded to the web or chords of a beam, is not permitted. In span structures of railway bridges fastening of webs of longitudinal or cross beams shall be arranged with the help of vertical angles and frictional connections. In span structures of all kinds of bridges, as a rule, the continuity of longitudinal beams over the total extent must be provided, but if there are discontinuities in the bridge deck – over the sections in between them.

4.121. For the improvement of aerodynamic stability of span structures of suspended and cable-stayed bridges it is necessary to increase their torsional stiffness by the erection of longitudinal bracing on the separate main beams or by design of closed box-section suspended girder, giving streamline form to it.

SECTION OF MEMBERS 4.122. The least thickness of parts of span structures and supports members is accepted in accordance with design calculations for strength, stability, endurance, stiffness and vibration, but not less than mentioned in Table 85.

Table 85 Structure members The least thickness or section of structure members, mm In railway bridges and

culverts laid under railway

In highway, city and pedestrian bridges and pipes laid under highway bridges

1. Corrugated sheets for metal pipes of common version

2 1.5

2. Ditto, for pipes of Northern version

2.5 2

3. Sheet articles (excluding those, 10 10

SNiP 2.05.03-84 Page 156

shown in items 4-9) 4. Hitch plates of main trusses and vertical webs of weld bent main trusses

12 10

5. Hitch plates of bracing 10 8 6. Straps in the butt joints of orthotropic plate ribs and connection plates

8 8

7. Gaskets 4 4 8. Horizontal base plate 20 20 9. Sheets of deck and rib of orthotropic plate

12 12

10. Angles in the major members of main trusses and deck plate

100x100x10 100x100x10

11. Angles of flanged fixings of longitudinal and cross beams

100x100x12 100x100x12

12. Angles in bracing members 80x80x8 80x80x7 The greatest permitted thickness of rolled stock, mm, is as follows: in faggots of parts, tied up with bolts of common type - 20; in welded members made of carbon and low-alloyed steel – 60; in cover plates and gusset plates if frictional connections are used – 16.

4.123. In order to reduce the number of connecting welds the sections of lattice truss composite members shall be designed from minimal number of parts.

4.124. In lattice main trusses the material of members, having box and H-shaped sections, shall be concentrated in sheets, located in the plane of the truss. Chords, compressed members of trusses and supports shall be designed, as a rule, of box section.

4.125. In composite members of lattice trusses the ratio θ of designed width b to the thickness t of plates shall not exceed the following values: for vertical and horizontal plates of box members – 60; for horizontal plates of H-shaped members – 45; for plates with free (unedged) overhangs – 20; for plates with overhangs, edged by angles or ribs, - 30; The designed width b of the plate is equal to: if two longitudinal edges are fixed: the distance in between the nearest marks of bolts, connecting the given plate to plates perpendicular to it or to connection bracing - for members with bolted connections; the distance in between axes of given plates – for welded and rolled stock members; b) if one longitudinal edge is fixed: the distance from the free edge of the plate to the nearest mark of the bolt – for members with bolted connections; the distance from the free edge of the plate to the axis of the nearest sheet, positioned in perpendicular to the given one.

4.126. In compressed members of H-section the thickness of horizontal plate shall constitute of the thickness of connected plates tf not less than: 0.4 tf - in members with bolted connections; 0.6 tf - in welded and rolled members if tf ≤ 24 mm, and 0,5 tf if tf > 24 mm.

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4.127. When designing units of trusses the localized stability of compressed zones of hitch plates shall be provided in accordance with item 4.55*, strengthening free edges, if necessary, with bordering angles or ribs.

4.128. Welded I-beams shall be designed from one vertical and two horizontal webs plates, but box-section beams shall be designed from two vertical and two horizontal plates, connected directly to the vertical plates by circuferential seams. If the required thickness of welded beam chord exceeds 50, 60 and 70 mm (in structures of common, Northern A and Б version accordingly), use of faggots, consisting of two plates, in chords is allowed. Change of section of a chord shall be made in the zone of its butt joints location, providing bevels by the width or by the thickness, but when necessary - by both of them simultaneously with the slope 1:8 for tensioned chord and 1:4 for the compressed one. In chords consisted of two plates, the latest must be different in the width by not less than 100 mm. In highway and urban bridges it is allowed to use in beam chords faggots formed of plates of the same width, connected with weld joints, overlapped on tangential edges with grooving thereof for the depth required by the design.

4.129. Exterior plate of the chord faggot, broken in the beam span, considering requirements of item 4.114, shall be extended behind the place of its theoretical breaking for the length, providing the fixing of 50 % of plate section area. The following must be provided: the thickness of this plate at the edge – 10 mm; symmetrical bevels by the width (reducing to zero) – with the slope 1:4; the bevel by the thickness – with the slope 1:8 for tensioned chord and 1:4 for the compressed one. For oblique joints at the end of the sheet the ratio of legs 1:2 (the smallest leg is on the vertical) and mechanical treatment for getting the smooth transitions (having radii not less than 5 mm) to the main metal of continuous chord plate shall be provided.

4.130. The centered transfer of pressure of sleepers to the webs of main or longitudinal beams shall be provided in railway bridges, having railroad bed with wooden sleepers, excluding contact of sleepers and members of longitudinal and cross bracing under the load.

WEB STIFFENERS OF FLEXURAL SOLID WEBS 4.131. *Sections of supports, in points of transmitting the concentrated forces (except bridge sleepers bearing points), in points of cross bracing location in flexural solid webs should include transverse web stiffeners, made of strips, angles or T-sections. Intermediate transverse and longitudinal web stiffeners shall be provided in accordance with calculations of local stability of webs for stages of fabrication, transportation, erection and operation. In absence of local pressure longitudinal web stiffeners shall be located from the compressed chord at a distance: with one stiffener – (0.20-0.25) hw; with two or three stiffeners: the 1st stiffener - (0.15-0.20) hw; the 2nd stiffener - (0.40-0.50) hw; the 3rd stiffener shall be located, as a rule, in tensioned zone of the web. Designed height of web hw shall be taken in accordance with Reference Appendix 28*. In beams with solid webs strengthened with transverse stiffeners only, the width of their projecting part bh shall be for the paired symmetrical stiffener not less than

for one-sided stiffener – not less than

thickness of stiffener ts shall be not less than

;4030

mmhw +

;5024

mmhw +

.2ER

b yh

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When webs are strengthened with transverse and longitudinal stiffeners, then inertia moments of their sections shall comply with the requirements of Table 86* for transverse stiffeners and of Table 87* for the longitudinal stiffener (with one longitudinal stiffener).

Table 86*

µ Is / (hwt3w) for transverse stiffeners

0.75 0.80 0.62 1.44 0.50 2.8 0.40 4.6 0.33 6.6

In Table 86* the following is designated: Is – inertia moment of transverse stiffener; hw – designed height of web, taken according to Compulsory Appendix 16*; tw – thickness of beam web;

α – distance between axes of transverse web stiffeners. Table 87*

h1 / hw Required inertia moment of longitudinal stiffener section Ist

Limiting values Ist

Minimal Maximal, considered in calculation

0.20 (2.5-0.5 α / h) x α2 t3w / h 1.5h t3w 7h t3w

0.25 (1.5-0.4 α / h) x α2 t3w / h 1.5h t3w 3.5h t3w

0.30 1.5h t3w -- -- In Table 87* the following is designated: h1 – distance from axis of longitudinal stiffener to axis of the nearest chord in welded beams or to the edge mark of flange angles in beams with bolt connections; α, hw – see designations in Table 86*; Ist – inertia moment of longitudinal stiffener section; tw – thickness of beam web. Note: When calculated Ist for intermediate values h1 / hw the linear interpolation is allowed. In span structures of all kinds of bridges the stiffeners can be positioned on one side of the web, and one-sided transverse and longitudinal stiffeners can be positioned on different sides of the web as well. Inertia moment of one-sided web stiffeners is calculated about an neutral axis of composite section, that includes the stiffener itself (flat, angle or T-section) and parts of the web with width b1 =θ1t, determined according to item 4.55*. Minimal sizes of projecting part of longitudinal web stiffeners shall be accepted according to above-mentioned requirements for transverse web stiffeners. When stiffeners of larger inertia moment are required to place, the transverse stiffeners in form of angles or T-section shall be used instead of stripped ones. Longitudinal stiffeners of T-section can be used for strengthening the web in case they are located inside the boxed part of the deck. In longitudinal stiffeners of angle steel, vertical flange must be overturned downward.

4.132. *In beam-welded web stiffeners in points of their connection to beam chords, to web stiffeners of other direction, and in the highway bridges to gussets of bracing welded to the beam web as well the round cutouts 120 mm high and 50 mm wide must be provided; bearing web stiffeners can be decreased by width up to 30 mm and by height up to 50 mm. .

;wh

a=µ

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4.133. Side faces of web stiffeners shall be fitted to the plate of beam chord in points of transmitting the concentrated forces. The ends of intermediate transverse stiffeners of welded beams shall be closely fitted , as a rule, to the chord plates of beams. For this purpose in all kinds of bridges the stiffeners ends can be fitted with special adapter pieces; in railway bridges it can be angle stiffeners fixed to the web by frictional connections, and in highway, city and pedestrian bridges the stiffeners can be welded to the chords. At this, the side faces of transverse stiffeners, which the roadway orthotropic deck transverse stiffeners are fixed to, shall be welded to the beam chords not depending on the type of structure version and stress sign in the chord, and following the requirements of item 4.168. Breaks of intermediate transverse stiffeners can be arranged on the web nearby the chords with breaking zone in conformity with the requirements of item 4.165.

4.134. Longitudinal stiffeners in welded beams shall be used only in that cases when local stability provided by installation of only transverse stiffeners and change of web thickness is not useful.

4.135. *Web- or flange-welded stiffeners parallel to the ready-made or erection butt joints of web or flange shall be distanced from them at least 10 tw in structures of common version and 20 tw in structures of Northern version. Front or back edges of the angle, used as a stiffener and connected with bolts to the web, shall be distanced at least 5 tw from the butt welded joint of web.

4.136. *Web stiffeners shall be welded with continuous double-sided joints Stiffeners and welds fixing them to the web are not permitted to break in points of crossing the butt joints of the web. In span structures of all kinds and versions in crossing points the longitudinal stiffeners and their joints must be performed as continuous, and the transverse stiffeners (except the bearing ones) must be broken and welded to them with fillets; the fillets in tensioned zone of a web should have leg ratio 1:2 (the biggest leg is on the longitudinal stiffener) and smooth transmission to the base metal. With breaking the longitudinal stiffeners at the bolted transverse butt joint of a web, the stiffener breaking zone shall be arranged in conformity with requirements of item 4.165.

PRESTRESSED DECKS 4.137. In continuous beams of uniform height, the tie beams shall be located in zones of maximal negative and positive moments. Prestressed solid web beam sections shall be designed as unsymmetrical with more developed compressed chord.

4.138. When prestressed beams are designed, it is necessary to provide tie beam connection to the chord by the length of the beam in four points at least, in such manner that to provide, if working under the load, their combined displacement in lateral direction and independent displacement in longitudinal direction.

4.139. Fastening of stiffeners or brackets, supporting the tie beams, shall be designed including friction forces developed under tension of tie beams.

4.140. The ends of tie beams shall be fixed on special remote rigid members – abutments. Beam members shall be reinforced for the impact of concentrated load in points of abutment fixing.

4.141. Providing for the stability of truss members to be compressed, tie beams are connected with bars by diaphragms. The distance in between fixing points shall be taken from the condition of free length bar stability, corresponding to length of these parts.

WELDED, FRICTIONAL AND BOLTED CONNECTIONS 4.142. When fixing with eccentricity is inevitable, in all-welded structures with one-web sections of members, they shall be fixed by the whole connection contour.

4.143. Drawings for steelwork of welded structures must indicate as follows:

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types, dimensions of all joints, symbols of prefabricated and erection joints. methods of welding (automatic, submerged arc welding, manual welding, etc.), type of weld backups for butt joints, and if necessary – sequence of welding; parts of weld joints with full penetration of member thickness; all points of the structure subject to the treatment in accordance with “Instructions on mechanical treatment of weld joints in steel structures of bridges” (Mintransstroy, МПС, 1978), with indication of relevant items. For weld assemblies and structures used for the first time the drawings of steelwork must indicate shapes of details with dimensions required for mechanical treatment of weld joints and stress concentration zones, and recommendations on execution methods.

4.144. When used the complicated rolled shapes (channels, T-section and I-section, including with parallel faces of flanges) the arrangement of cross joints and fixing to nodes with the help of welding is prohibited. In structures of highway, urban, and pedestrian bridges of common and northern versions it is allowed to apply welding by longitudinal continuous welds of continuous (less butts on the length) T and I-sections (including those of different numbers) with each other and to the plate attached all over the length of the butt or T-joint to the web of the shape; or by two fillets to the flange edges of the shape. In structures of mentioned bridges the nodal gussets and bracing gussets can be welded to the web of the shapes, taking measures to reduce concentration of stresses at the gusset ends in conformity with requirements of items 4.165 and 4.166, and web stiffeners can be welded only to the web of I-beams and T-beams as well.

4.145. It is prohibited to use plug welds in railway bridges, and in highway, urban, and pedestrian bridges they can used only for idle connections.

4.146. Fillets shall have, as a rule, concave outline of surface and smooth transition to the base metal. Transverse fillet welds, as a rule, shall be designed unequaled with a big leg directed along the force; at this, big–to-small leg ratio is recommended equal to 2.

4.147. Dimensions of fillets shall be specified as small as possible from the design of strength and endurance, at this taking into consideration technological requirements given below. Longitudinal connecting fillets of box-shaped, I- and H-shaped members, for steels and thickness of rolled stock, indicated in Table 47, should have the designed cross-sectional height at least 4 mm, and joints fixing the stiffeners to the beam web, and also longitudinal webs of orthotropic deck to the cap plate, - at least 3 mm. Length of transverse fillet weld or longitudinal fillet weld shall be not less than 60 mm and not less than 6-fold dimension of the weld leg.

4.148. Butt joints structure shall provide possibility to get full penetration of butted members designed thickness and smooth transition to the base metal.

4.149. If the butt joint is located transverse to the force in the member, the thickness of butt joint should be not less than the thickness of plated to be welded.

4.150. *In welded beams and composite members, which sections are formed with the help of connecting joints, the full penetration of T-joints and fillets is not required, if members under welding are broken in one section. If the break is not in one section, the full penetration of T-joint and fillet of members under welding shall be provided on length of 100 mm from the break. In break-working joints full penetration is obligatory. Application of weld assemblies functioning for break of members in the faggot, formed by the overlapped fillet welds, is not allowed. In corner joints of composite closed airtight members, formed by one-sided fillets, the penetration depth shall be not less than 4 mm when thickness of the thinnest plate is up to 16 mm, and not less than 5 mm when thickness of the thinnest plate is more than 16 mm.

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Intermittent welds can not be used for connection of separate members and fastening of structure members.

4.151. In structures with frictional connections the following shall be provided: free position of high-tension bolts, full tightening of faggots with bolts and screwing up of nuts, using dynamometric wrench and power nut-driver.

4.152. Bevel washers shall be used in connections of rolled sections with non-parallel surfaces of flanges.

4.153. Nominal diameters of holes for high-tensioned bolts in frictional connections are indicated in Table 88. Group of connections Nominal diameter of holes, mm, in frictional connections, if

the nominal diameter of the bolt, mm, is 18 22 24 27 Butt joints and fixings of main load-bearing members and bracing, defining the design position of the structure

21 25 28 30

Fixings: of bracing, not defining the design position of the structure; of fish-plates of longitudinal beams chords; of girders to resist braking and horizontal diaphragms of roadway

23 28 30 33

4.154. Connections shall be designed with the most compact position of high-tensioned and common bolts in accordance with norms of Table 89. Characteristics of the distance Norm The distance in between the centers of bolts: minimal in any direction maximal in any direction in the edge rows at tension and compression: in sheets in angles

2.5d* 7d or 16t 160 mm

maximal in the middle rows: transverse to the force at tension and compression along the force at tension along the force at compression

24t 24t 16t

The distance from the bolt center to the members edge: minimal along the force and by diagonal ditto, transverse to the force: in case of mechanically treated edges in case of rolled edges or edges after gas cutting, using the method “washing-out-process” and with oxygen curtain c) maximal

1.5d 1.5d 1.3d 8t or 120 mm

In Table 89 the following is designated: d - nominal diameter of a bolt; t – thickness of the thinnest member, positioned outside the faggot. * 3.0 d shall be specified for common bolts ** in case of two-rowed position, the norm is referred to the row at the front edge.

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4.155. The number of high-tensioned bolts shall be at least 2: in fastenings of bracing in main trusses and roadway part; in each longitudinal row of fastenings or butt strap (counting from an axis of butt joint). When fastening the bar with common bolts, the number of bolts in longitudinal row shall be not less than: in case of one row – 3 pcs; in case of 2 rows and more – 2 pcs; in projecting flange of short angle – 5 pcs. In butt joints and fastenings of tensioned and compressed-tensioned members the number of bolts in the first two transverse rows shall be taken the same (counting from the section of the member or of the strap with full force). The number of bolts in the consequent rows shall be increased gradually. In butt joints and fastening of angles with two-rowed position of bolts, the first bolt shall be positioned at the back edge. The number of bolt rows along the force (if the requirements of item 4/106 are observed) must be minimal. In longitudinal and transverse butts of beam webs the bolts can be mounted in one row each side of the butt.

4.156. The diameter of bolts mounted in angles of main members should not be more than ¼ of angle leg width. In bracing members, web stiffeners, diaphragms, etc. the bolts 22 mm in dia can be mounted in the leg of angle 80 mm wide, and of 24 mm in dia in the leg of angle 90 mm wide. In frictional connections with a large number of high-tensioned bolts, their diameter shall be specified as big as possible.

4.157. The total length of high-tensioned bolts shall be specified under provision that top of the tightened nut is below the border of bolt chamfer.

4.158. Butts of bolt-connected beam vertical web shall be covered with straps all over the entire height. Butt straps of flange angles can be applied in the form flat sheets.

4.159. Directly fixed area of through truss members in assemlies and butts shall be made up not less than 50 % of the whole net area of a member. With indirect cover of section area it is necessary to reduce eccentricity in fastening of straps and increase their length.

DETAILS OF STRUCTURES 4.160. Unconnected parts being in contact are not permitted in structures (except joining points of stiffeners to the beam chords) as well as slits, gaps, slots, troughs. In places of probable water accumulation it is necessary to provide drain holes in diameter not less than 50 mm. Steel ropes and bundles of high tensile wire, their anchors, points of connection and joining shall be securely protected from corrosion.

4.161. In tensioned members of symmetrical section, fitted with holes for connection of them with assembly hinged bolts, the net area of cut, passing through the bolt hole, should be not less than 140 %, but net area of cut from the end face of the member to the bolt hole - not less than 100 % of designed section of the member.

4.162. Branches of compressed composite bars with bolt connections and compressed-bent welded members as well shall be strengthened with transverse diaphragms in point of concentrated forces action. In welded box and H-shape truss members the diaphragms are recommended to weld to or fixed with bolts only to the vertical plates with gaps between diaphragms and horizontal plates not less than 50 mm.

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4.163. Auxiliary parts (brackets, members of handrails and sidewalks, navigation signs and signals, etc.) are not allowed to weld directly to the members of main beams and beams of roadway part as well as to the members of lattice main trusses. These parts can be welded only to transverse web stiffeners; in railway span structures of northern version the mentioned parts shall be fixed with the help of bolts. Spacers and diagonals of longitudinal bracing, spacers of transverse bracing are not allowed to weld directly to beam chords of span structures of all versions. In railway span structures it is prohibited to weld the members of longitudinal and transverse bracing to web stiffeners and gussets of bracing; the gaskets to the main members and in structures of northern version the stoppers to the beam chords as well.

4.164. *For provision of smooth (with radius not less than 15 mm) transition from weld metal to base metal in tensioned2on the stage of operation transverse butts of parts and members of railway span structures, it should be applied the mechanical treatment; this requirement is for the end parts of transverse butt joints of beam webs in size 40 % of tensioned zone height, but not less than 200 mm, counting from the tensioned chord.

4.165. For highway, urban, and pedestrian span structures in fixing the horizontal gussets of longitudinal bracing directly butted to the chords of solid webs it is necessary to provide the gusset full penetration and possibility of its non-destructive check. Also it is necessary to provide at the ends of gusset the shoulders and mechanical treatment of them together with the ends of welds in order to produce smooth transitions (with radius not less than 60 mm) to the chord.

4.166. For highway, urban, and pedestrian span structures with cross and sub-diagonal systems of longitudinal bracing located in the level, displaced relative to chords, for gussets tee-welded to the web it is necessary to provide stress concentration decrease measures mentioned in item 4.165. At this, for the provision of stability and elimination of chord vibration relatively the web it shall be fitted with cross web stiffeners in the plane of each assembly of bracing. If mentioned gussets are crossed with cross web stiffeners, the gussets and their welds must be arranged as continuous ones; the cross web stiffener members shall be welded to the gusset with fillets of leg ratio 1:2 (the big leg is on the gusset) and smooth transition to the base metal of the gusset.

4.167. In all-welded highway, urban, and pedestrian span structures the bracing elements lap welded to the gussets shall be fixed with two longitudinal fillet and two transverse fillet welds in accordance with item 4.142; bracing members from paired angles, symmetrically located relatively the gusset, can be fixed with two longitudinal fillet and one transverse fillet (end face) welds. The distance between welds of fixing the bracing members and welds fixing the gusset to the beam web as well as to the transverse web stiffeners shall be not less than 60 mm.

4.168. In case of welding the vertical diaphragms, web stiffeners and gussets joint plates to the tensioned chord in the deck the cross welds fixing the mentioned members, shall be designed with leg ratio 1:2 (the big leg is on the chord) and smooth transition to the base metal.

4.169. In structures of common version the stoppers can be welded to the upper chord of welded beams with longitudinal and transverse corner welds. At this, for transverse welds it is necessary to provide stress concentration decrease measures indicated in item 4.168, and also mechanical treatment to produce smooth transition (with radius not less than 5 mm) to the base metal.

2 The requirements to tensioned butt joints are also valid for compressed-tensioned ones.

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4.170. In designs of parts, that change the direction of steel cable (back-up devices, tower heads, etc.) or wires in cable (anchorages) and also that compact the cable (cable clamps, hanger clamps, etc.), it is necessary to use cable troughs of curvilinear cross section with rounding-offs at the end (in points of cable exit) and shortened (compared with the base) clamping straps, gaskets of aluminum (in accordance with item 4.4, н) or any other soft material. At this, to avoid the electrochemical corrosion, the steel cables and steel parts of mentioned devices being in contact with aluminum must be protected with cadmium or zinc coats 20 µm thick at least.

DESIGN OF CONNECTING PLATES AND PERFORATED SHEETS 4.171. In welded box-shape and H-shape members of main trusses of railway bridges the solid or perforated horizontal sheets only are allowed to be used. Connecting plates can be used only in bracing members of railway bridges and in those members of highway, urban, and pedestrian bridges that permit to connect the plates to the main parts of section without special measures on decrease of stress concentration.

4.172. The length of intermediate plates ls shall be not less than 0,75α, where α is a distance in between the rows of bolts (or welds) fastening the plate. The end plates in compressed and compressed- tensioned members shall be arranged 1,7 times longer than intermediate ones, but in tensioned ones – 1,3 times. The end plates shall be positioned as close as possible to the assembly. In welded box-shaped and H-shaped members the perforation can be brought to the end face of the member.

4.173. The number of bolts for the fastening of one plate side shall be not less than: for members working in live load – 4; for members working in dead load – 3; for idle members – 2.

PARTICULAR FEATURES OF BOLT-WELDED SPAN STRUCTURES 4.174. In bolt-welded span structures of northern version it is allowed to use the butt expansion pieces and in structures of common version – butt strap expansion pieces as well for attenuation of member section by bolt holes. At the ends of butt expansion pieces for attenuation (near the butt ) it is necessary to provide bevels and mechanical treatment of joints in accordance with requirements of items 4.128 and 4.164*. In butt strap expansion pieces for attenuation the bevels as per the width with slope 1:1 shall be provided. For skew welds the leg ratio 1:2 shall be accepted. For provision of smooth (with radius at least 5 mm) transition to the base metal the skew welds at the end of the expansion piece should be treated. Skew welds and parts of longitudinal joints up to the first row of holes must ensure the full fixing of the expansion piece area. The width of the expansion piece of steel of 16Д, 15 ХСНД and 10 ХСНД, 390-14Г2АФД and 390-15Г2АФДпс shall be not more than 44, 38 and 36 of its thickness, respectively. If the greater thickness is required, two separate expansion pieces are to be used, the distance between their joints should be 60 mm at least. The distance from the bolt center to the expansion piece end shall be not less than doubled diameter of the bolt hole.

4.175. For lattice bolt-welded trusses of highway, urban, and pedestrian span structures of common version it is allowed to use the assembly inserted gussets and attached gussets weld-connected to the chords. Assembly inserted gussets and attached gussets should have smooth transition (with radius at least 250 mm) to the chord. The distance from the chord butt and inserted gusset to the beginning of the shoulder in it should be taken not less than 70 mm. Butt joints of inserted gussets of tensioned and compressed-tensioned chords should be mechanically treated meeting requirements of item 4.164*. Inserted gussets must be fully penetrated with possibility of non-destructive checking and the gusset ends must be mechanically treated as well.

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4.176. Chord plates of longitudinal and cross beams can be of the length less than the length of web under provision of rectangular rounded (with radius 15 mm) cuts, vertical face thereof coincides with the end face of the broken chord plate. Such cuts shall also have gussets welded to the upper chord of the cross beam to increase the height of its web in zone of fastening to the main trusses. The structure of the gusset end junction to the chord of cross beam shall meet requirements of items 4.165 and 4.166. If breaking of the T-beam chord is required not forming the above mentioned cut in the web, the following must be provided: the chord to the place of breaking shall be beveled by thickness up to 6 mm with slope 1:8 and by width up to 32 mm with slope 1:4; places of fixing to the beam web on the length of beveled part must be fully penetrated. Also mechanical treatment of the chord end to produce smooth transitions (with radius not less than 60 mm) to the web (in both planes) shall be provided.

DESIGN OF ORTHOTROPIC DECK FOR ROADWAY PART 4.177. In highway, urban, and pedestrian bridges the orthotropic deck shall be designed as one-staged deck consisting of the floor plate reinforced with longitudinal and transverse ribs which vertical webs are welded to the floor plate with two-sided fillets. The long side of assembly blocks of orthotropic deck shall be oriented along the axis of a bridge.

4.178. In highway and urban bridges the thickness of the floor plate tmin shall be taken not less than 12 mm and not less than the value calculated by formula

where α – the distance between longitudinal ribs; P – maximal pressure to the plate from the concentrated load determined with allowance of pressure distribution by the floor structure; ξ = 7.8 or 15.6 – values of the coefficients, taken for structure of orthotropic decks with longitudinal ribs of strip and standard sections, respectively.

4.179. *In highway, urban, and pedestrian bridges the field joints of the floor plate of the upper orthotropic deck should be designed, as a rule, as welded ones. In the lower orthotropic decks, if it is proved by design, the field longitudinal welded joints of the horizontal plate with groove filling being incompletely full can be used. . Connection of the roadway floor plates of the orthotropic decks to the chords of main beams or trusses with overlapping welds is prohibited.

4.180. In orthotropic plates it is preferred to use open section longitudinal ribs made of strips, rolled T-bars, L-bars and welded T-bars, and in the railway bridges, as a rule, made of T-bars.

4.181. Field joints of the upper orthotropic decks longitudinal ribs shall be positioned in the third of the deck in between the cross ribs and, as a rule, should be frictional with prefabricated holes. In highway, urban and pedestrian bridges the field joints of the lower orthotropic deck longitudinal ribs shall be, as a rule, welded ones. Use of field joints of the orthotropic deck with longitudinal ribs inserts unwelded to the floor plate and breaking of the ribs in zone of field joint of deck blocks is not allowed.

4.182. Field joints of the web and chord of T-section transverse ribs should be, as a rule, frictional ones on high-tension bolts with prefabrication of full diameter holes.

4.183. Longitudinal ribs on places of crossing with the cross beams webs must be continuous. In highway, urban, and pedestrian bridges longitudinal ribs shall go through the cuts in the cross beams webs and be welded at the plant by fillet welds to the vertical face of the cut in the web or supporting plate (see Compulsory Appendix 17*, Table 1, items 17, а, б). Welding of the longitudinal rib faces to the cross beam webs is not permitted.

)236(,3min E

Pt ξα=

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4.184. Fixing of cross ribs of the upper orthotropic deck to the web stiffeners or special gussets of the main beams shall be, as a rule, frictional, on high-tension bolts.

4.185. The type of anti-corrosion coat of the floor plate and the type of road payment placed on the steel orthotropic deck shall be indicated in the design.

4.186. In railway span structures double-staged orthotropic decks with fastening the longitudinal ribs to the cross beams upper flange on frictional high-tension bolts, shall be used. In case if the floor plate is directly connected to beam webs it is allowed to fasten the longitudinal ribs to the cross beams flanges by tying devices of wire clamp type.

STRUCTURE OF BEARING PARTS 4.187. Beam span structures, having the deck length more than 25 m, must have movable bearing parts of hinge-roller or sector type. It is allowed (in seismic regions – it is recommended) to accept the bearing parts, using polymer materials.

4.188. If the distance between centers of bearing parts, located on the same support, is more than 15 m it is necessary to provide lateral mobility of one of the bearing parts by means of arrangement of bearing parts movable in two ways or by any other method. In railway bridges the lower rockers of unmovable bearing parts and plates of movable ones shall be fastened on the supports with anchor bolts. If requirements of item 1.40* is not met, the ends of decks shall be fastened to the supports with anchor bolts according to the design.

4.189. The structure of bearing parts shall provide the load distribution all over the area of deck node bearing and of bearing on the support.

4.190. As a rule, bearing parts of hinge-roller or sector type shall be cast with hinges of free tangency. It is allowed to use movable single-roller bearing parts made of high-tensile steel and also those having the overlay to surface of the roller and plate from hard materials. In movable bearing parts the number of rollers shall not exceed four. Rollers must be connected between each other by lateral tie bars, ensuring combined action of displacement and not preventing rolling and cleaning, and equipped with devices for elimination of lateral shift and longitudinal displacement, and protected by casings as well. In case of cylindrical rollers, having two flat faces, the possibility of turning over and seizure must be excluded.

5) COMPOSITE STRUCTURES GENERAL PROVISIONS

5.1. *Regulations of the present Section shall be observed when designing span structures, wherein reinforced concrete slab is integrated with steel main beams, trusses or roadway trusses for joint action.

5.2. Composite span structures of railway bridges except deck-type simple-beam ones with web slab shall be used only if approved by the Ministry of Railway Communication.

5.3. Quality requirements and design characteristics of composite structures materials as well as instructions on calculation and designing, which are not provided in the given Section, shall be taken as per Sections 1-4.

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DESIGNS GENERAL PROVISIONS

5.4. As a rule, designs shall be made basing on the Bernoulli’s hypothesis without regard for the compliance of joints, connecting steel and reinforced concrete parts. The compliance of joints is to be considered for beams less than 8 m long and lattice trusses with panels less than 8 m.

5.5. The reduction coefficient nb = Est/Eb is to be used in design of composite structures; in this case Est = 2.06 · 105 MPa (2.1 · 106 kgf/cm2) is the modulus of elasticity of steel part constructional metal, Eb – the modulus of elasticity in compression and tension of concrete, determined according to item 3.32*.

5.6. Calculations and types of inelastic deformations, accounted for in calculations, shall be taken in accordance with Table 90. As a rule, inelastic deformations are to be considered when calculating forces in members of statistically indeterminate systems. The approximate allowance for inelastic deformations of concrete is accepted, using conventional modulus of elasticity as per Compulsory Appendices 19 and 20.

5.7. Creep of concrete shall be considered when determining forces and moments from the dead loads and actions, if the utmost stresses in concrete caused by them exceed 0.2Rb, where Rb is design compressive strength of concrete as per item 3.24*. As a rule, in determining of the influence of concrete creep upon the composite structure the flexural rigidity EbIb of reinforced concrete part of the structure shall be considered. Creep of concrete is allowed to be approximately considered as per Compulsory Appendix 19, if EbIb ≤ 0.2 EstIs; here EstIs is flexural rigidity of steel part of the structure. Losses of stressed reinforcement tension due to the concrete creep as well as additional deformations due to compression of transverse joints of precast reinforced concrete panel shall be defined as per Compulsory Appendix 19.

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Table 90

Loads and actions Inelastic deformations considered in calculations for strength and

stability endurance crack resistance vertical and

horizontal ordinates of

camber statistically

determinate spans of railway

bridges

spans of highway and city bridges

for cracking for crack opening

rigidity (for structures with precast

panel)

Dead kr, us vkr, us kr, us kr, us kr, us -- kr, us Live vertical cr, pl vkr, us cr wud cr wud wud Temperature and shrinkage cr, pl -- -- wud cr -- -- Live transverse horizontal pl -- -- -- -- wud -- Due to transportation, erection, prestressing and adjustment

wud -- -- wud cr -- wud

In Table 90 the following is designated: kr - creep of concrete; us – compression of transverse joints of precast reinforced concrete slab; vkr – vibrocreep of concrete; cr – transverse cracks in reinforced concrete (due to all acting loads); pl – limited plastic deformation of steel and concrete (due to all acting loads and in checking of section only); wud – without regard for inelastic deformations; “--“ means that calculation is not made.

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5.8. Design for endurance of railway bridges zones, in which the live load increases the compressive stress in concrete, shall be calculated with regard for vibrocreep of concrete as per Compulsory Appendix 19.

5.9. Shrinkage of concrete shall be considered in the design for temperature action. In so doing, off-loading effect of concrete shrinkage is not considered. The ultimate relative strain of concrete shrinkage εshr shall be equal to 2 · 10-4 for cast-in-situ slab and 1 · 10-4 for precast slab. Stresses due to concrete shrinkage, balanced within cross section, are allowed to be defined as per Compulsory Appendix 20. Creep of concrete due to shrink stresses is allowed to be considered using in calculations conventional modulus of elasticity of concrete Eef, shr = 0.5Eb. 5.10. In calculations for temperature action the difference in temperatures of reinforced concrete and steel parts of sections shall be considered. As a rule, the difference in temperatures shall be determined on the basis of the thermal physical calculations. Calculations for temperature action can be made taking distribution of temperature in sections as being unchanged along the length of composite span structure and based on the following the greatest standard values of temperature difference tn,max of reinforced concrete slab and steel structure: a) for span structures with steel roadway web beam (dwg. 14, a):

30°C when steel temperature is higher then concrete one, and beam is heated by the sun rays, which are inclined at 30° and more to the horizon;

15°C when steel temperature is higher then concrete one but beam is not heated by the sun rays;

-15°C when steel temperature is lower then concrete one; b) for roadway span structures with lattice main girder:

15°C when temperature of trusses steel members is higher then the temperature of reinforced concrete independently on conditions of the sun lightning; -10°C when temperature of truss steel members is lower then the temperature of reinforced concrete;

c) for span structures with main web beams or lattice main girders and reinforced slab located between them of trough and half-trough types: 20°C when steel temperature is higher than reinforced concrete one; -15°C when steel temperature is lower than reinforced concrete one; d) 20°C when reinforced concrete temperature is higher than steel one for span structures of railway bridges with ballastless slab in the roadway and in spans of highway and city bridges of deck-type without (or before) placing of roadway pavement on the reinforced slab. Computation of forces and stresses due to the temperature action shall be made: for sub-item “a” – taking curvilinear diagram of temperature difference with the ordinate in i-point by the height of steel part section (dwg. 14, б)

where Zbl,i, hw are taken according to the drawing 14, a, cm; for sub-items “b” and “c”- taking rectangular diagram of temperature difference by the whole height of steel part section; for sub-item “d” – taking curvilinear diagram of temperature difference according to the drawing 14, в, and with the ordinate in i-point

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where Zbf,i, is taken according to the drawing 14, в, cm. Steel part of box section in span structures of deck bridges is allowed to be conventionally divided to beams of I-section, taking into regard for the difference of temperatures according to the drawing 14, б. It is allowed to calculate stresses due to changes of temperature, balanced within the cross sections, as per the Compulsory Appendix 20.

Drawing 14. Cross section of composite structures and design diagrams of temperature difference

а – cross section scheme; б - curvilinear diagram of temperature difference by the height of steel part section; в - curvilinear diagram of temperature difference for the top part of beam section.

5.11. Compressed reinforced slab shall be designed for strength, crack resistance, but in railway bridges – for endurance as well. The influence of development of limited plastic deformation of concrete and steel on force distribution in statistically indeterminate structures can be ignored.

5.12. Tensioned reinforced slab shall be designed for strength and crack resistance. Categories of requirements for crack resistance shall be taken as per the item 3.95*. Tension rigidity of reinforced slab with regard for cracks occurred shall be calculated by expression

here Er, Ar – modulus of elasticity and area of slab longitudinal reinforcement section, ψcr – coefficient considering partial involvement of concrete between cracks into the tension work and taken according to Table 91.

Table 91 Reinforcement Value of coefficient ψcr for

Railway bridges when designed for Highway and city bridges when designed

strength crack resistance for strength and crack resistance

Smooth reinforcement; tendons of high tensile wire; steel ropes

1.00 1.00 0.70

Deformed reinforcing steel bars

1.00 0.75 0.50

Forces in statistically indeterminate structures shall be defined considering influence of cross cracks in reinforced slab.

For precast uncompressed reinforced slab, wherein longitudinal reinforcement is not spliced, tension rigidity shall be equal to zero.

5.13. Designs of deck plate for local bending and collaboration with main beams can be made independently on each other, but forces and deformations shall be summarized only in case of plate behavior for local bending in longitudinal direction.

5.14. Cross section design shall be made stage by stage the number thereof is determined by the number of section parts, involved into the action in succession. Acting stresses for each parts of section shall be determined by summation of them as per stages of action.

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5.15. Design width of reinforced slab bsl, considered in the section, shall be defined as the sum of design values of slab overhang to the both sides from the axis of steel structure. (dwg. 15). As a rule, the design value of slab overhang shall be defined by spatial design; this value is accepted to be determined in accordance with Table 92.

Drawing 15. Scheme for definition of design width of reinforced slab, considered in the content of section

Table 92 Position of the slab overhang

relative to steel part, its symbol

Parameters of slab l Design value of slab overhang

Overhang in direction of neighboring steel member b

More than 4B Less than 4B

B/2 a + 6tsl,

but not more that B/2 and not less than l/8

Overhang in direction of cantilever bc

More than 12C Less than 12C

C a + 6tsl,c,

but not more than C and not less than l/12

The following is designated in Table 92: a – the half of the width of reinforced rib or haunch, but if they are not available, the half of the

width of reinforced slab and steel chord contact surface; tsl, tsl,c - the average thickness of reinforced slab in span and on the cantilever accordingly (rib of

haunch are not considered). l – parameter of the slab equal to: the length of the span – for main girders of trusses; the length of panel – for bridge deck stringers;

the distance in between main trusses or to the width of reinforced slab across the bridge, if the width is less than the given distance – for floor beam of bridge (see dwg.15); B – distance between axes of steel structures, equal by rigidity (see dwg.15) С - structural cantilever overhang of the slab from the axis of steel structure (see dwg.15).

5.16. The area of reinforced slab Ab, but in designs for torsion also its thickness tsl and width of the rib or haunch, shall be taken as divided to the reduction coefficient nb as per the item 5.5. When considering inelastic deformations it is allowed to use reduction coefficients calculated according to the conventional modulus of elasticity of concrete, defined as per Compulsory Appendices 19 and 20. The area of longitudinal reinforcement, which has bonding with concrete, shall be divided to the reduction coefficient nr = Est / Er, where Er – modulus of elasticity of untensioned Ers or stressed Erp reinforcement, taken as per Table 34. Grout, deck pavement and track structure in effective cross section should be ignored.

5.17. Centers of gravity of steel and reduced sections shall be determined according to gross section. Weakening of section by bolt holes is considered as per the item 4.24.

5.18. Strength and stability of steel beams when erection work is carried out are checked according to items 4.41, 4.42 and 4.51. Strength and crack resistance of structures and members thereof under prestressing, transportation and erection shall be checked with assumption of elastic work of steel and concrete. Checking shall be carried regardless of creeping and shrinkage of concrete and compression of transverse joints, but taking into consideration the influence of prestress losses as per the Section 3.

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DESIGN OF STRUCTURES STRENGTH DESIGN

5.19. *Design of composite beam for the action of positive bending moment1 shall be made by formulae of Table 93* as per one of design cases A, Б and В (dwg.16) depending on the value of stress in concrete σb on the level of center of gravity of reinforced concrete slab and stress in longitudinal reinforcement σb of concrete which reacts to concrete deformation under stress σb.

Table 93* Criterion of: (All formulae are used for strength criterion and checks in design cases А, Б and В) Ratio of rigidities in design case А

EbIb ≤ 0,2EstIs

none in design cases Б and В Ratio of stresses in concrete (compression “+”, tension “-“) in design case А

in design cases Б and В

Ratio of stresses in design longitudinal reinforcement (compression “+”, tension “-“) in design cases А and Б

in design case В Checks of: Reinforced concrete (compression “+”, tension “-“)

none in design cases А and Б in design case В

Steel upper chord (compression “+”, tension “-“) in design case А

in design cases Б and В

Steel bottom chord (compression “+”, tension “-“) 1 Bending moment that causes compression in the upper chord.

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in design case А

in design case Б

in design case В In Table 93 the following is designated:

M=M1+M2 - full bending moment (is taken as well as M1 and M2 with appropriate sign);

M1 - bending moment of the first stage of behavior (load is taken up by steel part of the structure);

M2 - bending moment of the second stage of behavior (load is taken up by composite structure), defined for statistically indeterminate structures, considering creep of concrete, transverse joints compression, formation of cross cracks in tensioned zones of reinforced slab and concrete shrinkage and change of temperature as well;

σbi, σri - stresses balanced in transverse composite section, arising on the level of gravity center of concrete cross section due to concrete creep, compression of precast plate cross joints, concrete shrinkage and temperature changes (except the case when reinforced slab temperature is higher than steel one as per the item 5.10.d., and calculations are made by formulae of Tables 93*-95) in concrete and longitudinal reinforcement accordingly;

As =As 1+Aw+As 2 -

net area of steel beam cross section;

As1, As2, Aw, Ab, Ar =Ars -

areas of cross section members of steel upper and bottom chords, steel vertical web, slab concrete, longitudinal unstressed reinforcement accordingly;

- moments of resistance;

Wbs =Is /Zbs - conventional moment of resistance on the level of gravity center of concrete section;

Is tb , Is - moment of net inertia of composite beam cross section, reduced to steel, and cross section of steel beam accordingly;

Zb.stb, Zbs, Zs1.s, Zs2.s - distance as per Drawing 16. nr=Est/Ers - coefficient of reduction taken as per the item 5.16;

nb - coefficient of reduction taken as per the item 5.5; εb,lim =0.0016 limited (for composite structures) relative deformation of concrete

on the level of its cross section gravity center; Ry, Rb, Rr = Rrs - design resistance of steel structure material as per the items 4.6* and

4.7*, concrete resistance to compression as per the item 3.24*, unstressed longitudinal reinforcement as per the item 3.37* accordingly;

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∂3=1+η(∂-1) - correction coefficient for moment of resistance when designing steel beam strength for collaboration of bending moment and axial force;

∂4=∂3/m1 - correction coefficient for moment of resistance when checking the upper steel chord taken as equal not less than 1.0;

∂ - coefficient taken as per the item 4.26*; η - coefficient taken as per Table 94; m - working mode coefficient of steel structure taken as per the item

4.19*; mb - working mode coefficient of concrete taken as per the item 3.25; mr - working mode coefficient of reinforcement taken as per the items

3.29*-3.45;

working mode coefficient of upper steel chord, which considers its unloading by adjacent understressed concrete and taken as equal not more than 1,2;

k - coefficient which considers increase of relative deformation of concrete under development of plastic deformations;

in so doing, k = 1, if

in case, if

then k is determined by interpolation between limiting values k = 1.0 and k = 1.0 + 0.0009Est/mRy. Case А Case Б Case В Drawing 16. Forces, stresses and deformations in composite cross section, which takes up positive bending moment

Table 94 As2/As1 Value of coefficient η when N/AsmRy is equal to

0 0.05 0.10 0.15 0.20 0.25 0.30 0.35

0 1.0 1.0 1.0 1.0 1.0 1.0 0.99 0.98 1.0 0.98 0.94 0.90 0.87 0.81 0.75 0.67

0.2 1.0 1.0 1.0 1.02 1.03 1.04 1.05 1.06 1.0 0.97 0.92 0.87 0.80 0.70 0.57 0.38

0.4 1.0 1.04 1.08 1.12 1.14 1.16 1.19 1.20 1.0 0.90 0.8 0.67 0.52 0.34 0.53 0.68

0.6 1.0 1.10 1.19 1.28 1.35 1.40 1.44 1.46 1.0 0.84 0.64 0.40 0.56 0.75 0.95 1.13

0.8 1.0 1.20 1.39 1.55 1.70 1.83 1.93 1.98 1.0 0.61 0.51 0.84 1.12 1.36 1.60 1.86

1.0 1.0 1.29 1.63 2.04 2.47 2.86 3.20 3.38 1.0 1.29 1.63 2.04 2.47 2.86 3.20 3.38

Table 94 (Continuation)

As2/As1 Value of coefficient η when N/AsmRy is equal to

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0.40 0.45 0.50 0.55 0.60 0.65 0.7

0 0.96 00.95 0.92 0.88 0.83 0.75 0.63 0.58 0.45 0.28 0.52 0.68 0.76 0.82

0.2 1.07 1.06 1.05 1.02 0.99 0.90 0.75 0.49 0.61 0.72 0.82 0.91 0.99 1.05

0.4 1.21 1.20 1.18 1.16 1.13 1.09 1.04 0.84 0.98 1.12 1.22 1.30 1.38 1.42

0.6 1.47 1.46 1.45 1.42 1.39 1.35 1.30 1.30 1.45 1.58 1.69 1.76 1.84 1.90

0.8 2.00 2.02 2.01 1.99 1.97 1.91 1.84 2.08 2.29 2.47 2.52 2.50 2.46 2.38

1.0 3.49 3.56 3.57 3.53 3.43 3.29 3.05 3.49 3.56 3.57 3.53 3.43 3.29 3.05

In Tables 93-95 the following is designated: N = Nbr = Abσb+ Arσr – in cases А and Г; N = Nbr,R = AbRb+ Arσr – in case Б when checking up the bottom chord; N = Nbr,R = AbRb+ ArRr – in case Б when checking up the upper chord and also in case В; N = NrR = ArRr – in case Б when checking up the upper chord and also in case В; N = Nr = Arσr, but not more than ArRr - in case Д when checking up the bottom chord. Notes: 1. Cases А, Б and В shall be taken as per the item 5.19* (dwg. 16), cases Г and Д- as per the item 5.21 (dwg. 17). 2. Here As2 – steel beam chord with the less area. 3. Values of η shown above the line are used in that case when stresses due to the moment and axial

force are summarized in the steel beam chords with the less area; values of η shown under the line are used in that case when stresses due to the moment and axial force are summarized in the steel beam chords with the biggest area.

4. Normal force N shall be taken as tensioning the steel beam in case of compressive stresses in reinforced slab and compressing the steel beam in case of tensile stresses in reinforced slab and reinforcement (in formula N shall have “+” sign in both cases).

5.20. If the neutral axis of the section is located within the height of reinforced slab and if stresses in tensioned part of the slab exceed mbRbt as per items 3.24* and 3.25, then only compressed part of concrete shall be included into the content of the section. Section strength check shall be done taking into consideration nonuniform distribution of stresses over the height of reinforced slab.

5.21. Design of composite beam for the action of negative bending moment3 shall be calculated by formulae of Table 95 by one of the design cases Г and Д (dwg. 17) depending on the value of stress in concrete σb on the level of reinforced slab gravity center.

Table 95 Criterion of: (All formulae are used for strength criterion and checks in design cases Г and Д) Ratio of rigidities in design case Г

EbIb ≤ 0,2EstIs none in design case Д

Ratio of stresses in concrete (compression “+”, tension “-“) 3 Which causes tension in the upper chord

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in design case Г in design case Д

Checks of:

Stresses in longitudinal reinforcement (compression “+”, tension “-“)

none in design case Г in design case Д

Steel upper chord (compression “+”, tension “-“)

in design case Г in design case Д

Steel bottom chord (compression “+”, tension “-“) in design case Г

in design case Д

In Table 95 the following is designated: M; M1; M2; σbi; σri; As2; Aw; Ab; Ar; As; Wb,stb; Ws2,s; Ws1,s; nr; nb; Ry; Rb; Rr; ∂3; η; m; mr; mb

- see designations for Table 93*;

Asψ =As + Ar /nrψcr; Wr,sψ = Isψ / Zr,sψ

- area, moment of resistance and inertia moment of net cross section of beam steel structure which collaborates with longitudinal reinforcement with area Ar/ψcr (reduced to steel structure material) accordingly;

Zbs; Zb,sψ; Zrs; Zr,sψ - distance as per Drawing 17; ∂5 = ∂3 / m2 - correction coefficient taken as equal not less than 1.0;

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- working mode coefficient of upper steel chord take as equal not more than 1.2;

Case Г Case Д

Drawing 16. Forces and stresses in composite cross section,

which takes up negative bending moment

5.22. Strength design of more complicated sections (for example, sections stressed by high-tensile reinforcement, double-plate sections in case of bending moment and external axial force combined action) shall be calculated considering their stressed state and structural particularities, in accordance with items 5.19*-5.21. Forces of prestressing shall be considered as an external load on the stage of reinforcement tension for sections with high-tensile reinforcement. On the next work stages, when determining unloading forces N, high-tensile reinforcement shall be considered together with concrete and unstressed longitudinal reinforcement, but in so doing, it is necessary to check additionally high-tensile reinforcement strength. In case Д high-tensile reinforcement shall be checked with regard for force increase in it in case of limited development of plastic deformations in steel structure. When section is effected by external axial forces Ne together with bending moments M additional bending moments arising due to the change of location of gravity center of studied part of section shall be considered.

5.23. Strength design of sections with reinforced slab, which behaves for local bending in longitudinal direction, shall be made according to design cases А, Б, В, Г and Д; in so doing, in cases Б, В and Д the slab shall be designed for the ultimate equilibrium as out-of-center compressed or out-of-center tensioned reinforced concrete bar in accordance with items 3.69, 3.70*, 3.72*, 3.73*, 3.75 and 5.13, but in design of the whole section unloading of its steel part by the resultant of compressive and tensile longitudinal forces, taken up by the slab, shall be considered.

ENDURANCE DESIGN 5.24. *Endurance design shall be done for: steel and reinforced concrete parts of the structure and also for structure uniting reinforced concrete with steel part of railway bridges; only for steel part of the structure and integration structure fastenings of highway, city and pedestrian bridges. In so doing, the high-tensile reinforcement bonded with concrete shall be referred to reinforced concrete part, but reinforcement not bonded with concrete – to steel part. In endurance design concrete inelastic deformations shall be regarded for as per items 5.6-5.8 and Compulsory Appendix 19. In endurance design the temperature action, concrete shrinkage and horizontal loads can be ignored. When calculating ρ = σmin / σmax the content of section shall include that part of concrete wherein there is no tension under considered loading. Endurance check shall be carried out with regard for requirements stated in items 3.91*-3.94* and 4.57*.

5.25. Endurance design for the railway bridge steel-concrete beam with unstressed reinforcement in reinforced concrete part of the section shall be calculated by formulae:

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where M1w - bending moment of the first stage of behavior due to loads considered in endurance design; M2w - bending moment of the second stage of behavior due to loads considered in endurance design, including bending moments from vibrocreep of concrete in statistically indeterminate structures;

Wi,stb – moment of net resistance of composite section for fiber i (bf, s1, s2), determined when coefficient of concrete to steel reduction Nvkr = Est / Evkr; Evkr - conventional modulus of elasticity of concrete taking into consideration its vibrocreep as per Compulsory Appendix 19; mb1 - working mode coefficient of concrete under multi-repeated load as per the item 3.26*; other designations correspond to accepted ones in items 3.94*, 4.57*, 5.19* and Drawing 16. If there are notches on the beam web the endurance of these points of section also shall be checked with substitution of relevant values of moments of resistance and coefficient γw in formulae (240) and (241).

CRACK RESISTANCE DESIGN 5.26. Crack resistance design of reinforced slabs in case of joint action with steel structures shall be done in accordance with requirements of items 3.95*-3.111*. In so doing, in calculations on crack formation the ultimate values of tensile and compressive stresses in concrete should be compared with stresses in the end fiber of concrete σbf of steel-concrete section with elastic behavior, calculated from operating loads taking into account inelastic deformations as per the item 5.6 on the stage of operation. In design for crack opening stresses in the end row of the reinforcement shall be calculated considering the increase of reinforcement area as per the item 5.12 and stress losses due to inelastic deformations. In case of unstressed reinforcement and behavior of the section by two stages, the tensile stress shall be calculated by formula

where M2 – bending moment of the second stage of behavior due to operating loads, determined for statistically indeterminate systems with regard for creep of concrete, compression of transverse joints, formation of cross cracks in reinforced slab tensioned zones, and concrete shrinkage and temperature changes as well; Other designations are described in items 5.12, 5.19*, 5.21 and Drawing 17.

5.27. Crack opening (in case of two stages of behavior) in tensioned precast reinforced slab, unstressed reinforcement thereof in transverse joints is not butt-joined, shall be calculated by formula

where σ2,s2 – tensile stress in steel upper chord arising due to loads and impacts of the second stage of behavior with the assumption that there is no reinforced slab in the zone of tension; la – the distance in between integration structures at the transverse joints; the length of the slab block, if integration structures are not available; Zbf,s, Zs2,s – the distance as per Drawing 17;

)242(,,

,2ri

srcr

bib

srrcr

bibsbr An

AWn

AZMσ

ψσ

ψ

σσ

ψψ

ψ −++−

=

)243(,.2.2

,2

,. dcra

st

s

ss

sbfdcr l

EZZ

a ∆≤⋅=σ

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∆cr,d = 0.03 cm – limiting width of crack opening in the transverse joint, which has reinforcement for transfer of transverse forces; if the reinforcement is not provided in the joint, ∆cr,d shall be calculated in the assumption that transverse force is not transferred through the joint. When arranging glued joints the crack resistance of reinforced slab of railway bridges shall be checked as per the category 2a of crack resistance requirements; when checking crack resistance of reinforced slab of highway, city and pedestrian bridges the value of tensile stresses shall not exceed 0.5 Rbr,ser (according to Table 23). If glued joints are used in prestressed reinforced slab its crack resistance shall be taken according to the item 3.95*.

DESIGN OF INTEGRATION OF REINFORCED CONCRETE SLAB WITH STEEL STRUCTURE

5.28. Integration structures shall be designed for shearing forces SQ in integrating joints due to cross forces and for longitudinal shearing forces SN arising from temperature actions and concrete shrinkage, anchoring of high-tensile reinforcement, action of adjacent cable stay or diagonal, etc. Besides above said, integration structure located at the end parts of reinforced slab shall be designed for tearing forces including those resulting from temperature actions ands concrete shrinkage.

5.29. Shearing force acting over the integrating joint of reinforced slab and steel structure shall be defined by formula

where σb1, σb2 – stresses in the centers of gravity of concrete cross section accordingly in the right and left sections of designed part of the slab having the length ai; σr1, σr2 – stresses in longitudinal reinforcement in the same sections accordingly; Ab, Ar – as per the items 5.19* and 5.21. If tensile stresses in reinforced slab exceed 0.4 Rbt.ser, then shearing forces shall be determined in the assumption of crack availability in the slab and stresses shall be calculated in reinforcement σr taking into account slab longitudinal rigidity as per the item 5.12. Complete end shearing force Se shall be determined taking σ as being equal to 0 at the end and the length of the end designed part as being equal to ae = 0,36(H+bsl), (245) where H – designed height of cross-section of composite members; bsl – as per the item 5.15; The distribution of shearing forces between reinforced slab and steel structure in complicated cases of actions may be taken as per Compulsory Appendix 21.

5.30. The end forces Sab, that break off the reinforced slab from steel structure, shall be determined by formula where Zb,s2 – the distance from the center of gravity of concrete cross section to the upper fiber of steel structure; Se, H, bsl – as per the item 5.29.

)244(),()( 2211 rrbbrrbbi AAAAS σσσσ +−+=

)246(,6.5 2,e

sl

sbab S

bHZ

S+

=

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Tearing force Sab shall be taken as being applied at the distance 0.024 (H+bsl) from the end of the slab (see Drawing of Compulsory Appendix 21).

5.31. Design of integration structure of steel part with concrete one shall be done: a) in case of rigid supports – assuming as being rectangular the diagram of compressive stresses,

transmitted by the design crushing surface of support; b) in case of vertical flexible supports – basing on the conditions of bending behavior of support

with crushing of concrete as per Compulsory Appendix 22; c) in case of inclined anchors – basing in the anchor behavior on combination of tension and

bending with crushing of concrete as per Compulsory Appendix 22; d) in case of embedded slab members, connected with steel chords by high-tension bolts – basing

on the design of frictional connections with high-tension bolts as per items 4.100* and 4.101; e) in case of integrating joints with high-tension bolts, compressing reinforced concrete – basing

on the behavior conditions of integrated part for friction over the joint contact surfaces as per Compulsory Appendix 23;

f) in case of bolt-glued integrating joints – in compliance with sub-item d) or e), but with regard for cohesive force due to glueing.

5.32. *Design of integration structure on rigid support shall be calculated by the following formulae: In railway bridges: strength design Sh ≤ 2RbAb,dr; (247) endurance design Sw ≤ 1.5mblRbAb,dr; (248) In highway, city and pedestrian bridges: strength design Sh ≤ 1.6RbAb,dr; (249) where Sh, Sw – shearing forces, falling at one support, in strength and endurance designs accordingly; Ab,dr – area of concrete crushing by support; in case of cylindrical and arc-shaped supports – area of their diametrical section; mbl – as per the item 5.25. In case of pre-cast reinforced slab and location of supports in holes the design resistance Rb shall be taken according to concrete class, but the thickness of grouting shall not be included into the crushing area. If supports are located in longitudinal joints of the slab the crushing area shall be completely regarded for, but design resistance shall be taken according to the class of concrete for joint filling. If rigid supports are located in the reinforced rib or haunch, the limiting values of Sh and Sw shall be reduced, multiplying the right parts of formulae shown above to 0.9 when 1.5bdr ≥ brib>1.3bdr and to 0.7 when brib≤1.3bdr, where bdr – the width of area of concrete crushing by support;

5.33. Fastenings of integration structures to steel part shall be designed as per items 4.82* - 4.102. Designs for fastenings of rigid support to steel part shall be made with regard for moment from shearing force.

5.34. If rigid supports and inclined anchors are used simultaneously in integration structures it is allowed to consider their joint action, assuming that apparent resistance of integrating joint is equal to the sum of resistance of supports and anchors.

CHECK OF RIGIDITY, DETERMINATION OF CAMBER AND DESIGN OF HORIZONTAL LOADS

5.35. Vertical deflections resulting from loads and also displacement when determining periods of vibrations shall be calculated with the assumption of elastic behavior of concrete independently on the sign of stresses occurred in it.

SNiP 2.05.03-84 Page 181

When calculating periods of free horizontal vibrations, the deflection of reinforced slab in the horizontal plane shall be determined with introduction of protective layer, preparation for water proofing, ballast trough edges and reinforced concrete footways to the content of section. When designing camber of span structures with precast slab, the concrete shrinkage may be ignored.

5.36. In single-track railway span structures the reinforced slab shall be checked for strength in horizontal plane as a compressed-bent (or tensioned-bent) reinforced members, which is acted by the axial force due to collaboration with steel structure and by bending moment due to horizontal loads. In so doing, temperature action and concrete shrinkage are allowed to be ignored. If slab concrete is in plastic stage due to vertical loads actions and forces of prestressing and does not take up horizontal bending moment, so the latter can be taken up by the steel part off the structure. In so doing, total relative deformations in concrete εb,lim with regard for horizontal bending moment shall not exceed 0.0016.

DESIGNING 5.37. Reinforced slab shall be connected with steel girders and trusses along their total length. The required degree of crack resistance shall be provided by reinforcing or prestressing.

5.38. The thickness of reinforced slab shall be not less than indicated one in item 3.117. The thickness of reinforced slab of sidewalk cantilever, considered in the content of net section, shall be at least 8 cm.

5.39. As a rule, integration of precast reinforced slab with steel structure shall be arranged using frictional, bolt-glued and welding joints. Integration may be also provided using supports and anchors, filled with concrete in holes and joints of precast reinforced slab. The gaps in between support and the structure of plate block shall be at least 5 and 3 cm accordingly along and across the span structure. Arrangement of supports and anchors is not permitted in cavities and grooves closed from the top and if it is difficult to fill them with concrete. When arranging intermittent integrating welds the strength of reinforced slab for local bending behavior in between bearing points shall be provided; in so doing, the height of the gap in between the slab and chord shall be enough for chord painting.

5.40. The placement of integration structures shall meet the following requirements: the clearance in between rigid supports and anchors shall not exceed 8-fold average slab thickness, calculated by the division of slab area involved into collaboration to its design width; in so doing, the slab area shall be taken considering area of the rib or haunch; clearance in between the rigid support shall be not less than 3.5-fold height of design area of concrete crushing by support; clearance in between anchors shall be not less than 3dan, where dan is the diameter of anchor bar. The minimal distance for placement of high-tension bolts, compressing the reinforced slab, shall be taken as per Table 96.

Table 96 Standard size Minimum limit distance, mm, if bolt diameter is 22 24 From the hole center to the edge of reinforced concrete member

100 120

Between hole centers in all directions 140 160

5.41. The structure of rigid supports shall provide the uniform concrete deformations over the area of crushing and shall not cause concrete splitting by corners.

SNiP 2.05.03-84 Page 182

In case of convex form of surface, transferring pressure from support to concrete (cylindrical supports, etc.), the zone of concrete local compression by support shall be reinforced.

5.42. As a rule, anchors shall be arranged in the form of loops, located at the angle of 45° to the direction of shearing forces. It is allowed to use single reinforced anchors. In embedded members loop reinforced anchors shall be used, as a rule, together with rigid supports.

5.43. When using high-tension bolts for integration of precast reinforced slab with steel chords the following is required: high-tension bolts holes shall be of increased diameter, ensuring bolt positing wityh regard for tolerances, stated by norms of fabrication and erection; to provide the possibility for elimination of leakages at the expense of distortion of steel sheets when tightened, use of flexible gaskets, etc.

5.44. Reinforced slab shall be anchored against its breaking off from steel part. When using rigid supports, which do not provide filling of reinforced slab with concrete, additional measures against breaking off shall be taken. If shearing force may change the direction of action in integration with inclined anchors, it is necessary to position inclined anchors of counterdirections or combination of inclined anchors with vertical ones.

5.45. Transverse butts of precast reinforced slab blocks shall be arranged using: glueing of surface end faces with compression of butts by the force, which creates pressure on the end surface at least 0.5 MPa (5 kgf/cm2); welding of starter bars and subsequent filling of joint with concrete.

5.46. In case of precast reinforced slab, integrated over the total block length, a layer off concrete or mortar, protecting the upper chord from corrosion, shall be provided in between steel upper chord and reinforced block. If the thickness of concrete or mortar is 5 cm and more it must be reinforced.

6) WOOD STRUCTURES Not translated yet.

7) BASES AND FOUNDATIONS GENERAL PROVISIONS

7.1. *The bases and foundations of the bridges and culverts shall be designed in conformity with requirements of SNiP 2.02.01-838, SNiP 2.02.03-85, SNiP 2.02.04-88, SNiP II-7-81* and requirements of the present Section.

7.2. The soils for bases shall be classified in conformity with GOST 25100-82.

7.3. The soil physical properties characteristic values required to calculate the rated resistance of bases under the foot of shallow foundations or caisson foundations (as per Obligatory Appendix 24) shall be determined following the instructions of SNiP 2.02.01-83*.

7.4. Standard and designed values of physical-and-mechanical properties characteristics of material used for foundations shall fit the requirements of Sections 3, 4 and 6.

DESIGNS 7.5. The bases and foundations of bridges and culverts shall be calculated as per two groups of limiting states: the first group – on carrying capacity of base, foundation security against sliding and turning over, stability of foundation when affected by frost heave forces, as per strength and stability of foundation structure;

SNiP 2.05.03-84 Page 183

the second group – on deformations of bases and foundations (settlement, roll, horizontal displacement), crack resistance of reinforced structures of foundations (by instructions of Section 3).

7.6. *Water buoyant effect to soils and parts of the structure located below surface or underground water level shall be included into designs on carrying capacity of base and on stability of foundation position if foundations are embedded in sand, sandy loam, silts. Embedding of foundation on loam, clays and rocks require to consider water buoyant effect in cases when it creates the more unfavourable designed conditions. Water level is taken as the most unfavourable one – the lowest or the highest.

7.7. *.For soil bases under the shallow foundations, designed with ignoring the fixing in the ground, the position of designed loads resultant (towards centre of gravity of foundation bottom area) characterized by relative eccentricity shall be limited with values indicated in Table 107.

Table 107 The maximum relative eccentricity e*0/r for bridge piers under

action of abutments under action of

Location of bridges dead load only

dead and live loads in the most unfavourable combination

dead load only

dead and live loads in the most unfavourable combination

Railways of general purpose and of industrial enterprises, detached tracks of subway

0.1

1.0

0.5

0.6

Highways (including industrial enterprises and intra-economy motor roads), streets and roads of cities, villages and rural populated areas:

0.1

1.0

0.8

large and medium-size 1.0 small 1.2 ________ * Eccentricity eo and core radius of foundation section r (at its foot) is determined as follows.

Where M - moment of forces applied about the main central axis of foundation foot; N - resultant of vertical forces; W - moment of resistance of foundation foot for less stressed rib; A - area of foundation foot. _____________________________________________________________________ The load resultant location at a level of the abutment foundation foot with the approach embankment more than 12 m high shall be checked considering the vertical pressure of adjoining embankment weight. In this case a relative eccentricity to the side of deck shall be not more than 20% of values indicated in Table 107. If the relative eccentricity exceeds the unity the base foundation foot maximum pressure shall be determined by the triangular form diagram built within the compression part of the base.

( )278,A

WrandNMeo ==

SNiP 2.05.03-84 Page 184

7.8. Carrying capacity of the base under the foot of the shallow foundation or caisson foundation with separate design of piers as per live loads acting along and across the bridge shall satisfy the conditions

Where p, pmax - foundation foot average and maximum pressure, relatively, onto the base, kPa (tf/m2); R - rated resistance of rock or soil base against axial compression, kPa (tf/m2), determined in accordance with Obligatory Appendix 24.; γn - construction purpose safety factor, determined equal to 1.4; γc - behavior condition coefficient taken equal to: 1.0 – in determination of carrying capacity of soil bases in case of action of the live loads Nos 7-9; 1.2 - in determination of carrying capacity of rock bases in case of action (besides live loads Nos 7-9) of one or several live loads Nos 10-15 and 17.

7.9. In calculations of carrying capacity of bases for shallow foundation and caisson foundation the stresses occurring in soil under their foots from the loads Nos 10-14 (as per the item 2.1* including the corresponding coefficients of load combinations as per the item 2.2) shall be specified separately along and across the bridge axis, and the most unfavourable stresses shall be summed with the stress from the dead and live vertical loads. In pile foundations the forces originating in piles from the above mentioned loads, acting along and across the bridge axis, shall be summed.

7.10. In calculations (as per soil and material) of structures of pile and caisson foundations (except calculations of carrying capacity of bases) the designed soil surface shall be taken as follows: for abutment foundation it is natural soil surface and for bridge piers foundations it is soil surface near piers at a level of cutting (leveling) or local scour, determined according to instructions of items 1.25-1.30, at designed and maximum consumption [for calculations on action of design (end) and service loads, respectively]. For abutments and land bridge piers with pile foundations, which grillages are located above the soil and piles are sung through the filled or sluiced part of the embankment, the design soil surface can be specified taking into account the fixing of piles in this part of embankment.

7.11. *.Carrying capacity of the single pile in unfrozen soils with action of axial compressive or pulling out force shall be determined according to SNiP 2.02.03-85, in frozen soils – according to SNiP 2.02.04-88.

7.12. Carrying capacity of the base in a level of pile bottom is required to be checked as for the conventional foundation according to Obligatory Appendix 25*. The mentioned check is not required for: one-row foundations in any soil conditions; multi-row pile foundations, which piles work as the posts (when supported them onto rock soils, large fragmented soils with sand filler, clays of hard consistency and frozen soils used by principle 1).

7.13. If under the bearing ground layer taking up the pressure of foundation foot or lower ends of piles there is a layer of not so hard unfrozen or melted everfrozen ground, the carrying capacity of this layer shall be checked according to Obligatory Appendix 26.

7.14. The stability of shallow foundations on unfrozen or melted everfrozen grounds against turning over or flat displacement (sliding) shall be designed in accordance with Section 1, taking in the calculation of shear the following coefficient of friction of masonry against the surface: rock with saponified surface (clayer limestone, shales, etc.) a) wet condition - 0.25 b) dry condition - 0.30

,maxn

c

n

RpandRpγ

γγ

≤≤

SNiP 2.05.03-84 Page 185

loam and sandy loam - 0.30 sand - 0.40 gravel and pebbles - 0.50 rock with unsaponified surface - 0.50

7.15. The stability of foundation on unfrozen or melted everfrozen soils against deep shear (displacement together with soil by the most unfavourable surface of sliding) shall be designed for the bridge piers located on the hillsides and for the abutments in all cases when the embankment is over 12 m high, and in cases of unfrozen or melted clay soil in foundation bases or the interlayer of water-saturated sand with clay soil underneath when the embankment is 6-12 m high.

7.16. *.Settlement and roll of shallow foundations on unfrozen soils shall be designed according to SNiP 2.02.01-83* and on the permafrost soils, according to SNiP 2.02.04-88. Calculations of settlement of the abutments with the embankment over 12 m high shall include an additional lateral pressure onto the base from the weight of adjacent part of the approached embankment, determined according to the Appendix 27.

7.17. Settlement of pile or caisson foundations shall be determined according to instructions in the item 7.16*, considering such foundation as conventional one in shape of rectangular parallelepiped of dimensions taken according to Obligatory Appendix 25*. The pile foundation settlement can be taken equal to settlement of the single pile by data of static test of it in the same soils with observing one of the following conditions. piles function as the posts number of pile longitudinal rows is not more than 3.

7.18. When determined the foundation settlement according to items 7.16* and 7.17 for design surface of soil it is taken its natural surface (without regard for cutting and scour ). Foundation settlement on unfrozen soil can be not determined: - when foundation rests onto rock, large-fragmented soil with sand filler and hard clays – for all bridges; - when foundation rests onto other clays - for bridges of outside statically determinate systems of span up to 55 m long on the railway and up to 105 m long on the highway.

7.19. Stress in concrete of the grillage from pressure of piles end-face, as a rule, should not exceed rated resistance of the grillage concrete as per rates of axial compression in strength designs. If the stress exceed the rated resistance of concrete in the grillage, it is required to apply the concrete of higher class or to provide the placing of reinforced meshes of rods 12 mm in diameter above each pile (one mesh if stresses exceed the rated resistance of concrete of the grillage up to 20 %, or two meshes if stresses exceed the rated resistance of concrete of the grillage up to 20-30 %).

DESIGNING 7.20. *The bridge and culvert foundations shall be embedded to soil to a depth determined by calculations of carrying capacity of bases and foundations according to items 7.5 – 7.18 and accepted not less than values required by SNiP 2.02.01-83* and SNiP 2.02.04-88 for shallow foundations, SNiP 2.02.03-85 and SNiP 2.02.04-88 for piles and grillages. Minimum distance between piles in plan shall be specified according to SNiP 2.02.03-85 and SNiP 2.02.04-88. Within water currents the bridge foundations shall be embedded to soil below the level of local scour determined according to instructions of items 2.25* - 1.30 at designed and maximum water discharge, to a depth required by calculation for the action of design (end) and service loads, respectively.

SNiP 2.05.03-84 Page 186

7.21. *.Dimensions in plan of the grillage of pile foundations shall be specified on the base of distances between the pile axes as per SNiP 2.02.03-85 taking into consideration the pile embedding accuracy tolerances, established in SNiP 3.02.01-83, as well as by provision between piles and grillage vertical faces of clear distance not less than 25 cm; with shell piles of diameter more than 2 m – not less than 10 cm. The grouting bed placed by submarine method is prohibited to be used as a working (bearing) part of the grillage.

7.22. *.Piles shall be embedded to the grillage (above the layer of concrete placed by submarine method) to a length determined by calculation and accepted at least as a half of prismatic piles perimeter, and 1.2 m - for piles of diameter 0.6 m and more. Piles can be embedded to the grillage with a help of longitudinal reinforcement free lengths determined by calculation but not less than 30 diameters of bars for deformed bars and 40 diameters of bars for smooth bars. At this, the piles shall be brought into the grillage 10 cm at least.

7.23. Reinforced grillage shall be strengthened as per calculation in conformity with the instructions of Section 3. Concrete grillage shall be strengthened structurally in its lower part (in space between piles). Cross section area of reinforcing bars along and across the bridge axis shall be taken not less than 10 cm 2 per 1 m of grillage.

7.24. Strength of the mortar used to seal the piles or end-bearing piles in wells bored in rock shall be not less than 9.8 MPa (100 kgf/cm2), and in other soils – not less than 4.9 MPa (50 kgf/cm2).

7.25. The cutting edge of foundation when located within fluctuations of water and ice levels shall be chamfered by size not less than 0.3 x.3 m, and foundation should be given the streamlined shape.

7.26. With necessity to arrange the benches of foundation their dimensions shall be proven by design , and the surfaces connecting the inner ribs of benches of concrete foundation can not deviate from the vertical at an angle above 30°. Inclination to the vertical of side faces of the open caisson (or the ratio of well benches total width to the embedding depth ), as a rule, shall not exceed 1:20. Larger inclination is allowed on the condition that measures are taken to ensure the well submergence with the target accuracy.

APPENDIX 1*,

Compulsory

CLEARANCES TO BRIDGE STRUCTURES ON GENERAL HIGHWAYS , INTRA-ECONOMY MOTOR ROADS IN KOLKHOSES, SOVKHOSES AND OTHER AGRICULTURAL ENTERPRISES AND ORGANIZATIONS, ON ROADS TO INDUSTRIAL ENTERPRISES, AS WELL AS ON STREETS AND ROADS IN CITIES, VILLAGES, AND RURAL SETTLEMENTS 1. The present Appendix establishes clearances to bridge structures: it is limit cross outlines (in plane perpendicular to longitudinal axis of the bridge roadway) within that no any member of the structure itself or device mounted on this structure should protrude. Note. Conventional symbol of clearances is the letter Г , dash, and figure equal to a distance between the railings. 2*. Clearance diagrams to highway and city bridges having no car-track are given in Dwg.1, the left side of each diagram presents the case when the sidewalk adjoins to the railings, and the right side is for the case of detached location of sidewalks. Drawing 1. Clearance Diagrams to Highway and City Bridges. a) No median б) Median less crash-barriers

SNiP 2.05.03-84 Page 187

в) Median with crash-barriers Symbols on the clearance diagrams: nb - total width of roadway or width of roadway for one-way traffic n - number of traffic lanes and b – width of each traffic lane are taken: for bridges on general highways as per Table 4 in SNiP 2.05.02-85; on intra-economy roads as per Table 24-26 in SNiP 2.05.07-91; on streets and roads in cities, villages and rural settlements – as per Table 8 and 9 in SNiP 2.07.01-89*; h - clear height (distance from roadway surface to the top of outline ) taken for

bridges on : general highways, intra-economy motor roads and on streets and roads in

cities, villages and rural settlements – not less than 5.0 m; roads to industrial enterprises – not less than the height specified for

vehicle running plus 1 m, but not less than 5 m; П - safety strips C - separating strips (in multilane traffic in each direction), which width is

equal to distance between edges of roadways of different directions ЗП - protection strips which width, as a rule, shall be specified equal to 0.5 m;

for timber through bridge – 0.25 m; Г - distance between crash barriers that includes the width of median having no

railings T - width of sidewalks as per item 1.64* h - clear height (distance from roadway surface to the top of outlines), taken for

bridges : on highways of category I-III, on streets and roads in cities, villages and

rural settlements – not less than 5.0 m; on highways of category IV and V, and intra-economy motor roads – not

less than 4.5 m; on motor roads, category III-п and IV-п, to industrial enterprises - not less

than the height of vehicles supposed to circulate plus 1 v, but not less than 5 m;

a - height of crash-barriers in conformity with instructions of item 1.65*; hT - clear height on sidewalks taken not less than 2.5 m.

3. Clear width of bridges located on highways of general use, intra-economy roads in kolkhoses, sovkhoses and other agricultural enterprises and organizations, roads to industrial cities as well as on streets and roads in cities, villages and rural settlements in absent of the car-track shall be specified as per Table 1*.

Table 1* Category Width, m Location of

bridge Num.of lanes

Width of card, m

Clearances Safety strip П

Road-way nb

General highways, I 6 2.5 Г-(13.25+С+13.25) 2.0 11.25х2 access and intra- 2(Г-15.25) roads of industrial enterprises (less circulation of 4 Г-(9.5+С+9.5) 7.5x2 very heavy trucks) 2(Г-11.5) II 2 Г-11.5 2.0 7.5 III Г-10 1.5 7.0 IV Г-8* 1.0 6.0 V 1 Г-6.5** 1.0 4.5 Г-4.5 0.5 3.5 Intra-economy 1-c 2 2.5 Г-8* 1.0 6.0

SNiP 2.05.03-84 Page 188

motor roads in kolkhoses, II-c 1 Г-6.5** 1.0 4.5 sovkhoses and Г-4.5 0.5 3.5 other agricultural enterprises and III-c 1 Г-4.5 0.5 3.5 organizations Streets and roads Arterial 8 2.5 Г-(16.5+С+16.5) 1.5 15x2 in cities, villages, freeways, 2(Г-18) and rural and general settlements streets of 6 Г-(12.75+С+12.75) 11.25x2 continuous 2(Г-14.25) traffic 4 Г-(9.0+С+9.0) 7.5x2 2(Г-10.5) Controlled 8 2.5 Г-(15.0+С+15.0) 1.0 14x2 traffic 2(Г-16) arterial roads and 6 Г-(12.75+С+12.75) 10.5x2 general 2(Г-14.25) streets 4 Г-(12.75+С+12.75) 7x2 2(Г-14.25) 2 Г-9 7 Main traffic- 4 Г-16 14 -pedestrian Г-(8.0+С+8.0) 7x2 streets of 2(Г-9) regional importance; streets and roads to

scientific-and

2 Г-9 7

-production, industrial, municipal- 2.5 1.0 storage areas; roads and main streets in villages Main 2 Г-10 8 pedestrian- traffic streets of regional importance Streets and 2 Г-8 6 roads in

local

building area, park roads _______________ *Clearance Г-7 can b e used for timber bridges (except glued timber bridges). **Ditto, clearance Г-6. Notes. 1. In column “Clearances” figures above the line denote clearance of bridge with roadway having no railings on median, and figures under the line denote clearance of bridge with roadway having railings or in case of separate span structure for each way of traffic.

SNiP 2.05.03-84 Page 189

2. In cases unforeseen in Table 1* (especially for bridges on industrial enterprises motor roads with circulation of very heavy trucks) the bridge width clearance shall be specified by formula: Г = П + nb + C + nb + П; Г = П + nb + П; 3. Safety strip width (ПI) shall be specified depending upon the design traffic speed established for the road (using the data given in Table 1*). For bridges on roads to industrial enterprises (including with circulation of very heavy trucks) the width of safety strip shall be specified П = 1.50 m. 4. Logging and service roads of logging enterprises: clearance of bridge (including timber bridge) on roads of category IV shall be specified equal Г-8 with width of the roadway 6.5 m and safety strip 0.75 m.

5. If the given area uses agricultural machines, having dimensions exceeding ones given in Table 1*, then on the apoproval of Subjects of Russian Federation the bridge clearances shall be enlarged depending upon the ground clearance (superelevation over the pavement) of parts, protruding beyond the outer surface of wheel tyres or crawlers. If the ground clearance of protruding parts is less than 0.35 m (for timber bridges less than 0.30 m), the clearance of the bridge shall be specified 1 m more wide than dimensions of machine in moving position. If the ground clearance of protruding parts is 0.35 m and more (for timber bridges 0.30 m and more), the clearance of the bridge shall be specified 1.5 m more wide than a distance between outer surfaces of wheel tyres or crawler of agricultural machine. 4. Clearance diagrams for city bridges with car-track shall be specified in accordance with Dwg.2 (symbol as per the item 2 of the present appendix) and the data of Table 1*. Clear width for bridges used only for car-track (two tracks) shall be specified not less than 9.0 m. 5. On combined bridges when located two-lane roadway one lane from each side of railway tracks or the subway tracks the clear width on erach traffic lane shall be not less than 5.5 m. 6. Safety strips of width less than indicated in Table 1* can be specified in availability of relevant feasibility study: for bridges over 100 m long on highways of category I-III and III-п and over 50 m long on highways of category IV and IV-п, if the bridges are located at a distance over 100 km from the largest cities and over 50 km from other cities, and designed traffic intensity decreases 2 times and more compared with subburban parts of the mentioned highways; in case of locating the bridges on parts of highways where shoulders are reduced in width: during reconstruction of bridges; on underpasses in availability of speed change lanes ((from the side of these lanes); on bridges with the climbing lane (from the side of this lane). In this case the safety strip shall be not less than 1.0 m wide on bridges of highways, category I-III and III-п and 0.75 m wide on bridges of highways, category IV and IV-п. Notes. When safety strip width is specified less than indicated in Table 1* the traffic signs for traffic control are required to be installed. Drawing 2. Clearance diagrams to city bridges with car-track I. car-track is axially located on the bridge; II. car-track is displaced relative to the bridge axis; a – separate bed; б – general bed Legend a - П is specified as per item 2*; б - subgrade edge; b - is specified by structure of crash-barries Dwg.3. Clearances diagrams to underpasses 1 – cross roads have no crash-barriers; II - when piers are installed on median and there are crash-barriers; a – category I-III; III-п and IV-п; б – category IV and V. 7.* When designed the bridge on curves in plan the roadway shall be broadened depending on category of the roads in accordance with the requirements of SNiP 2.05.02-85 and SNiP 2.07.01-89*.

SNiP 2.05.03-84 Page 190

Highway bridge roadway can be broadened by means of narrowing the safety strip provided the observance of all dimensions of the strip as per the item 6 or by means of enlarging the bridge clearances. 8. The bridge median width shall be, as a rule, equal to that on the highway or street. The median width on the large bridges can be decreased in availability of relevant feasibility study , but it should be specified not less than 2.0 m plus the width of railings. 9. Clearances to underpasses through highways shall correspond to values given on Dwg.3. When piers are installed on medians a distance from the roadway edge to the face of median shall be not less than, m: on highways of category I – 2.0 (including safety strip 1.5 m); on city roads and streets - 1.5 (including safety strip 1.0 m). Clear height for underpasses through city streets and roads shall be specified: in case of no car-track - as per item 2* of the present appendix; in case with car-track - as per Dwg.2. Clear height for underpasses through highways of category III-п and IV- п shall be specified as per item 2* of the present appendix. Note. When determined the underpass span structure bottom elevations as well as the position of upper braces in through bridges it is necessary to take into account that the roadway level can be raised after its repair for a thickness of new (additional) layer of pavement surface. 10. Distance from the cross road subgrade edge to the upper face of unretaining-type abutments or to the cone of fill in case of retaining-type abutment shall be not less than values indicated in Table 2.

Table 2 Minimum distances , m from subgrade edge of crossed roads when designed

underpasses with number of traffic lanes

Category of crossed roads Pedestrianbr

idges 2 4 6 8

I, II, III, III-п, IV- 2.0 3.0 4.0 5.0 6.0

V 1.0 1.5 2.0 3.0 4.0

V, I-c 0.5 0.5 0.5 0.5 0.5

The bridge pier side surfaces (from the side of road) shall be designed outside the subgrade of crossed roads at a distance not less than 2 m in case of column through piers and in case of solid walls not less than 4 m on roads of category I-III and 0.5 m on roads of category IV and V. In crossing of city highways and streets the supports of all types shall be installed at a distance not less than 1,0 m from the crash-barrier (curbstone), and in absence of crash-barrier not less than 1.5 m from the street roadwayedge. Walls (abutments) of city underpasses of tunnel type shall be located on the boundary of clearances to underpasses in accordance with Dwg. 3.

APPENDIX 2

for reference

COMBINATION COEFFICIENT η FOR LIVE LOADS AND FORCES

Nu

mb

e

r s of

lo ad

s

(f or

c ed

)

mo

s

t un

f

a vo

ur

a bl e fo t th e gi ve

n

de

s

i gn

Nu

mb

e

rs

o

f

co

mb

in

at

io

ns

o

f

lo

ad

s

(f

or

ce

s)

a

ct

in

g

si

mu

lt

an

eo

us

ly

o

r

in

a

pa

rt

w

it

h

th

e

mo

st

u

nf

av

ou

ra

bl

e

• Coefficient η at different combinations of live loads and forces

SNiP 2.05.03-84 Page 191

No.

7 (li

ve v

ertic

al lo

ads)

No.

8 (E

arth

pre

ssur

e fr

om m

ovin

g

ve

hicl

es)

No.

9 (C

entri

fuga

l for

ce)

No.

10 (T

rans

vers

e im

pact

s of

mov

ing

vehi

cles

)

No.

11 (B

rake

or t

ract

ion

forc

e)

No.

12 (W

ind

load

)

No.

13 (I

ce p

ress

ure)

No.

14 (V

esse

l im

pact

)

No.

15 (T

empe

ratu

re c

limat

e ef

fect

)

No.

16 (E

ffec

t of s

oil f

rost

he

avin

g)

No.

17 (C

onst

ruct

iona

l loa

d)

No.

18 (S

eism

ic lo

ads)

S (F

rictio

n or

resi

stanc

e ag

ains

t sh

ear i

n be

arin

g pa

rts)

1

0,5

—

' —

—

—

—

—

1 0.8 0.8 0,7

0,7

0,25 0,5

'0,25 0.5

0,7 0,7

0.7

—

—

—

0,7 0,7

0,7 0.7

0,25 0,5

7 и 8

9 10*

8. fl, 12 И 15 9,12,13,15 и S 10, 13, 15 и S

10 и 14 , lt<:iZM-15: . 12, 13 и 15

1 ' 1

0,8 0,8 0.8 0.8 0,8 0,8

1 1 ^ 0,8

0,8 0,8 0,8, 0,8 0,8

0,25

0,7

0.7 0,7 0,7 0,7 0,7

—.

0,5

0,25 0,5

—

—

—

9

11, 12 и 15 12. 13, 15 и 5'

14

0,8 0.8 0.8

0,8 0.8 0,8

0,8 0,8 0,8

—

0,7

0.25

0,7

0,7

0,7 0,7

—

—

0,7

10*

,7, 8, 13, 15 и S 7,8 и 14

0,7 0,7

0.7 0.7

;. —.. ,

0,8 0,8

•и.

0,7

0,7

0,7

—

—

—

. 0,7

0,5

11

7- 9, 12 и 15

0,8

0,8

0,8

0,8 0,25

0,7

—

0,5

0,7

0,25 0,5

0,7

0,25 0,5

0,7

0,25 .0,8

0,7 0,7 0,7

0.7 0,7 0,7

—

0,5 0,8

«

12*

7-9 7, 8, "11 и 15 7-9, 13, 15 и Д 13, 15, 17 и S 15—17 и S

0,5

0,7 0,7

0.7 0,7 0,7 0,7 0,7

1 1

0,7 0,7 0,7

—

—

0,5

—

—

—

0,7 0,7

0,7 0.7

0,7

0,7

—

0,25 0,7

—

—

—

—

13

7-9, 12, 15 и 5 7, 8, 10, 15 и S

12, 15 и S

0,5

1 0,7

0,7 0,7

0,7 0,7 0,7

0,7 0.7 0,7

Continued Appendix . 2*

Коэф ф ициент ri при различных комбинациях временных нагрузок и воздействий

Num

ber o

f loa

ds

(for

ces)

the

mos

t un

favo

urab

le fo

r a

give

n de

sign

I

Num

ber o

f co

mbi

natio

n of

load

s (f

orce

s) a

ctin

g si

mul

tane

ousl

y or

sepa

rate

ly

with

the

mos

t un

favo

urab

le

No.

7 (li

ve

verti

cal l

oads

) No.

8 (E

arth

pr

essu

re fr

om

mov

ing

ve

hicl

es)

N

o/9

(cen

trifu

gal

forc

e)

No.

10

(tran

sver

se

impa

cts o

f m

ovin

g

vehi

cles

No.

11 (B

rake

or

trac

tion

forc

e)

No.

12 (w

ind

load

)

No.

13 (i

ce

pres

sure

)

No.

14 (v

esse

ls

impa

ct)

No.

15

(tem

pera

ture

, cl

imat

e ef

fect

) N

o.16

(eff

ect

of s

oil f

rost

he

avin

g)

No.

17

(con

stru

ctio

nal

load

s)

No.

18

(ear

thqu

ake

load

ing)

S

(fric

tion

or

resi

stan

ce

agai

nst s

hear

in

bea

ring

parts

)

SNiP 2.05.03-84 Page 192

14

—

—

—

—

—

—

—

• 1

• —

' —

—

—

• '7-9

0,7

0.7

0,7

—

—

• — -

—

0.8

—

~

— .

—

—

• 7. 8 и 10

0,7

0.7

...—

0.7

—

—

—

-0,8

—

—

— •

—

— 15

—! '.'•"'

• — •

— •:••

— •

—•

—

—

—:.;..

:.-,;—11:.;

1

—

. —

—

—

7—9, 11 и 12

0.7

0,7

.0,7

— '

0.7

0,5 0,25

—

'—•-.

0,8

—

—

—

—

7—9, 12, 13 и S

0,7

0,7'

0,7

—

—

0.5^ 0.25

0.7

—'

0,8

—

—

—

0,7

7,.^, 10. 13 и 5

0,7

0,7

— ..

• 0,,7

. \~-.''

^;;-.,'

0,7,

—

.0,8

— .

—

—

0,7

0,7

•.12. 13, 17 и 5

—

—

'•—- 0,5

0,7 . \

0,8

—

1

0,7

0,7

.;12. 16,'17 и S

0,5

0,8

0,7

1

0,7

•(6

—

—

'1.— •

—

—

—..

—

• —

—

—

1

—

••— '

—

0,7

12. 15.17 и S

0,5

0,7

0,8

1

0,7

17

• —

—

— .

—

—

—

—

— •

—'

'. —

—

1

.—

—

0,7

12, 13, 15 и S

• —

0,5

0,7

0.7

— ^

1

—

0,7

0,7

12,'15, 16 и 5

—••

0,5

'

0,7

0,7

1

0,7

0,7

0,7

0.7

0,7

18***

•7-9, 11 и. 5 0,3

0,3

—

—•

—•

—

0.8

0,7

S

— ...

—

—

. •—

—

—

—

., —'

—

—

—.

—

—

1

0,5

7-9, 12. 13,15

0,7

0,7

0,7

0,25

0,7

— •

0,7

i

0,8

7, 8, 10. 13, 15

0,7

0,7

—

0.7

—

—

0,7

—

0,7

—

—

—

0.8

0,7

12, 13, 15, 17

•—

0,5

0,7

— •

0.7

1

—

0,3

12, 15-1.7

:

•

0,7

'

0,7

0,7

1

'

'0,8

0.5

.

i

' When bridges are located on ig radius curves (when centrifugal force is not large) the load No.10

must be considered as accompaning to loads No.7 and No.8; " Refer to note 1 to item 2.2 of Section 2. "" Refer to item 3 to item 2.2 of Section 2; Note. Above the line it is given coefficients of combinations taken in designing the railway bridges and of subway bridges; under the line – coefficients of combinations for motor road bridges and city bridges.

APPENDIX 3

compulsory

METHODS OF DETERMINING THE RESULTANT OF CHARACTERISTIC HORIZONTAL (LATERAL) PRESSURE TO BRIDGE PIERS FROM DEAD WEIGHT OF EARTH 1. The resultant of characteristic horizontal (lateral) pressure Fh to piers of bridge from the dead weight of fill-up earth as well as earth laying beneath the natural ground surface at a depth of foundation footing embedding 3m and less (Dwg,, a) shall be determined as follows

)1(21 bhpF xhh =

SNiP 2.05.03-84 Page 193

where ph - characteristic horizontal (lateral) pressure of earth at a level of bottom surface of the layer under consideration, specified according to the item 2.6; hx - fill-up height, measured from rail foot or top of pavement surface, m; b - reduced (average by height hx) width of pier in plane of rear faces, onto which the horizontal (lateral) pressure of earth is distributed, m. Dwg. Diagrams of earth pressure to piers of bridge to determine the resultant of characteristic horizontal (lateral) pressure to piers a – at a depth of foundation footing embedding 3 m and less; б – ditto, more than 3 m; 1 – the first layer; 2 – the second layer; 3 – the third layer The arm of the resultant Fh from foundation footing shall be specified equal to z = 1/3 hx. For solid (including U-shaped) and hollow (with longitudinal openings) abutments if the opening width b1 equals or less than double width of wall b2, as well as for solid (less openings) foundations the width b shall be taken equal to a distance between outer faces of structures. For hollow (with longitudinal openings) abutments or for separate (with openings) foundations, if b1 > 2b2, the width b shall be specified equal to double total width of walls or separate foundations. For pile or column abutments, if the total width of piles (columns) equals or more than a half of the total width, the width b shall be specified as a distance between outer faces of piles (columns); if the total width of piles (columns) is less than a half width of the pier, then the width b shall be specified for each pile (column) as its double width. Notes. 1. Values γn and ϕn when determined the pressure ph for the full height hx can be specified as for the drainage soil of fill. 2. For piles driven into the constructed before (compacted) embankment the horizontal (lateral) pressure is ignored. 3. Horizontal (lateral) pressure of earth to piers from the side of the span shall be accounted, if the construction project provides measures ensuring the action stability of this earth during the construction and operation of the bridge. 4. The abutment rear face inclination and forces of friction between fill-up soil and the face are ignored when determined the force Fh. 2. When the foundation footing embedding depth is above 3 m the resultant of horizontal (lateral) pressure of each i- (from the bottom ) layer of soil laid lower than natural ground surface shall be determined by the following formula

where γi - earth specific weight of layer under consideration Hi - thickness of layer under consideration τi - coefficient of characteristic horizontal (lateral) earth pressure

for i- layer, equal to

ϕi - characteristic value of earth layer internal friction angle H0i - reduced to earth filling specific weight total thickness of earth

layers laying above the upper surface of the layer under consideration.

For example, for the lower (first) layer the thickness given in Dwg., б is

)1()2(21

0 bhhhpF iiiiih += τ

°−°= )2()2

45(2 ii tg ϕ

τ

)3(33220

x

xxi

hhhh

γ

γγγ ++=

SNiP 2.05.03-84 Page 194

The arm of the resultant of i- layer pressure from the bottom surface of the layer under consideration shall be equal to

APPENDIX 4*

Compulsory

METHODS OF DETERMINING COEFFICIENT OF VERTICAL EARTH PRESSURE WHEN DESIGNED LINKS (SECTIONS) OF PIPES 1.* Coefficient of vertical earth pressure for reinforced concrete and concrete links (sections) of pipes Cν shall be determined by the following formulae.

Where ϕn - characteristic angle of internal friction of pipe filling earth; τn - coefficient of characteristic horizontal (lateral) pressure of

filling earth, determined by formula (6), item 2.6; d - diameter (width) of link (section) as per outer contour, m; h - height of filling when determined vertical pressure by

formula (4), item 2.6, measured from rail foot or top of pavement surface to top of link (section), m; On determination of horizontal (lateral) pressure by formula (5), item 2.6 the filling height hx shall be taken up to the middle of pipe link (section) height;

a - distance from base of embankment to top of link (section) of pipe, m;

S - Coefficient, specified equal to: 1.2 - for inflexible foundations (on rock base or on column piles); - for low-flexible foundations (on suspended piles); 1.0 - for mass shallow foundations and ground (no rock) bases.

If

then it shall be taken Coefficient of vertical earth pressure for multiple-hole round pipe culvert can be calculated by the following formula Where nv = 0.01 (l/d)2 + 0.02 (l/d) + 0.9, but not more than 1

( here l is a clear distance between openings of pipes)

)4(23

3 0

0

ii

iiii hh

hhhz++

=

)1()2(1 nnv tghdBBC ϕτ−+=

)2(,3hsa

tgB

nn ϕτ=

,dhB f

,dhB =

)3(1vvv CnC =

SNiP 2.05.03-84 Page 195

On additional fill-up of embankments where natural compaction of filling earth took place and the pipe structure is in satisfactory physical condition it is permitted when determined characteristic pressure to the pipe from dead earth weight to specify a nondimensional coefficient C equal to 1, not depending the flexibility of foundation. 2. When calculated flexible (from corrugated material, etc.) links (sections) of pipes and when determined the pressure to ground (rockless) bases, the coefficient Cv shall be specified equal to the unity.

APPENDIX 5

Compulsory

CHARACTERISTIC LIVE VERTICAL LOAD CK FROM MOVING RAILWAY TRAIN AND RULES OF LOADING THE LINE OF INFLUENCE WITH THIS LOAD 1. Table 1 gives values of characteristic equivalent loads v for loading the one-valued and separate sections of two-valued lines of influence. In cases described below when loaded the lines of influence it is required to apply the loads – uniform 9.81K kN/m (K tf/m) of track and from moving train with empty cars, given in the item 2.11. 2*. The computation of bridge members shall take into consideration transfer and distribution of pressure by members of permanent way, at this the equivalent load v shall be specified: a) when determined local pressure transferred by bridge sleepers as well as metal fasteners (with rubber gaskets) in laying the rails on the reinforced concrete slab - equal to 24.5K kN/m (2.50K tf/m) of track; for computation of beam web firmness – not more than 19.62K kN/m (2K tf/m).

Table 1 Intensity of equivalent load v, kN/m (tf/m) of track, at

K=1 K=14 Length of loading,λ, m α=0 α=0.5 α=0 α=0.5

1 49.03 (5.000) 49.03 (5.000) 686.5 (70.00) 686.5 (70.00) 1.5 39.15 (3.992) 34.25 (3.493) 548.1 (55.89) 479.5 (48.90) 2 30.55 (3.115) 26.73 (2.726) 427.7 (43.61) 374.2 (38.16) 3 24.16 (2.464) 21.14 (2.156) 338.3 (34.50) 296.0 (30.18) 4 21.69 (2.212) 18.99 (1.936) 303.7 (30.97) 265.8 (27.10) 5 20.37 (2.077) 1782 (1.917) 285.2 (29.08) 249.5 (25.44) 6 19.50 (1.988) 17.06 (1.740) 272.9 (27.83) 238.8 (24.35) 7 18.84 (1.921) 16.48 (1.681) 263.7 (26.89) 230.7 (23.53) 8 18.32 (1.868) 16.02 (1.634) 256.4 (26.15) 224.4 (22.88) 9 17.87 (1.822) 15.63 (1.594) 250.2 (25.51) 218.9 (22.32) 10 17.47 (1.781) 15.28 (1.558) 244.5 (24.93) 214.0 (21.82) 12 16.78 (1.711) 14.68 (1.497) 234.9 (23.95) 205.5 (20.96) 14 16.19 (1.651) 14.16 (1.444) 226.6 (23.11) 198.3 (20.22) 16 15.66 (1.597) 13.71 (1.398) 219.3 (22.36) 191.8 (19.56) 18 15.19 (1.549) 13.30 (1.356) 212.7 (21.69) 186.0 (18.97) 20 14.76 (1.505) 12.92 (1.317) 206.6 (21.07) 180.8 (18.44) 25 13.85 (1.412) 12.12 (1.236) 193.9 (19.77) 169.7 (17.30) 30 13.10 (1.336) 11.46 (1.169) 183.4 (18.70) 160.5 (16.37) 35 12.50 (1.275) 10.94 (1.116) 175.0 (17.85) 153.2 (15.62) 40 12.01 (1.225) 10.51 (1.072) 168.2 (17.15) 147.2 (15.01) 45 11.61 (1.184) 10.16 (1.036) 162.6 (16.58) 142.2 (14.50) 50 11.29 (1.151) 98.75 (1.007) 158.0 (16.11) 138.3 (14.10) 60 10.80 (1.101) 9.807 (1.000) 151.1 (15.41) 137.3 (14.00)

SNiP 2.05.03-84 Page 196

70 10.47 (1.068) 9.807 (1.000) 146.6 (14.95) 137.3 (14.00) 80 10.26 (1.046) 9.807 (1.000) 143.6 (14.64) 137.3 (14.00) 90 10.10 (1.030) 9.807 (1.000) 141.4 (14.42) 137.3 (14.00) 100 10.00 (1.020) 9.807 (1.000) 140.0 (14.28) 137.3 (14.00) 110 9. 944 (1.014) 9.807 (1.000) 139.3 (14.20) 137.3 (14.00) 120 9.895 (1.009) 9.807 (1.000) 138.6 (1413) 137.3 (14.00) 130 9.865 (1.006) 9.807 (1.000) 138.1 (14.08) 137.3 (14.00) 140 9.846 (1.004) 9.807 (1.000) 137.9 (14.06) 137.3 (14.00)

150 and more

9.807 (1.000) 9.807 (1.000) 137.3 (14.00) 137.3 (14.00)

Notes: 1. Equivalent loads calculated in kN/m of track with values of parameters 1.5 ≤/≤ 50 m (α=0 and α=0.5) and λ > 50 m (α=0), are produced by the formula

Where e = 2.718… - natural logarithmic base. 2. For intermediate values of loading length λ and intermediate positions of influence line vertex α = α/ λ ≤ 0.5 the load values v shall be determined by the interpolation. Dwg.1. Coefficient e in dependence upon λ and α (length of loading λ, m, is shown in the diagram) b) when determined local pressure transferred by ballast pocket (in all cases) as well as when determined the forces to calculate the slab across the track - equal to 19.62K kN/m (2K tf/m) of track; along the track – not less than 19.62K kN/m (2K tf/m) of track. Notes*: 1. When the track is arranged on the ballast, the value v ≤ 19.62K kN/m (2K tf/m) at λ ≤ 25 shall be taken (including for the pier design if the ballast layer is continuous) corresponding to α=0.5 not depending on position of the influence line top. 2. In calculation of the ballast pocket slab the value of the load shall be taken equal to v/b kPa (tf/m2),

where b - load distribution width, m, taken equal to 2.7+h or 2.7+2h ( it depends on what is more unfavorable when calculated the separate sections of slab), but not more than a width of the ballast pocket.

H - distance from sleeper foot to slab top, m 3*. In case of curvilinear, toothed (close to triangular) and tetragon outlines the single-valued influence lines and separately loaded parts of two-valued influence lines with coefficient of distortion ψ < 1.10 (ratio of influence line triangular area to area of influence line under consideration at the same lengths of influence lines and the same their maximum ordinates) are loaded with equivalent load v according to the item .2* of the present Appendix. 4. in case of curvilinear outline the single-valued influence lines and separately loaded parts of two-valued influence lines with coefficient of distortion ψ ≥ 1.10 and length λ ≥ 2 m are loaded according to i.2* of the present Appendix taking into account the following instructions. a) at 1.10 ≤ ψ ≤1.40 (except the case when the track is arranged on the ballast and λ < 50 m) with increasing the intensity of the equivalent load to the value , % , equal to e (ψ - 1), where e is the coefficient determined by Dwg. 1. when the track is arranged on the ballast and λ < 50 m, the value v shall be taken as per Table 1, at this, for λ ≤ 10 m not depending on influence line top position - as per column corresponding to α=0.5. b) when ψ > 1.40 it is necessary to sum from loading the parts of influence line. Top included part of the influence line of length λ1 and area A1 (dwg.2), bordered by ordinates y1 and y2 is loaded for maximum (in accordance with λ1 and α1); the other part of influence line (A – A1) is loaded with the load 9.81K kN/m (K tf/m) of track.

,)4

1)(149.43787.10807.9( 204.0 Ke

αλ

γ λ −++=

SNiP 2.05.03-84 Page 159 Notes*: 1. When the track is arranged on the ballast, the value v ≤ 19.62K kN/m (2K tf/m) at λ ≤ 25 shall be taken (including for the pier design if the ballast layer is continuous) corresponding to α=0.5 not depending on position of the influence line top. 2. In calculation of the ballast pocket slab the value of the load shall be taken equal to v/b kPa (tf/m2),

where b - load distribution width, m, taken equal to 2.7+h or 2.7+2h ( it depends on what is more unfavorable when calculated the separate sections of slab), but not more than a width of the ballast pocket.

H - distance from sleeper foot to slab top, m 3*. In case of curvilinear, toothed (close to triangular) and tetragon outlines the single-valued influence lines and separately loaded parts of two-valued influence lines with coefficient of distortion ψ < 1.10 (ratio of influence line triangular area to area of influence line under consideration at the same lengths of influence lines and the same their maximum ordinates) are loaded with equivalent load v according to the item .2* of the present Appendix. 4. in case of curvilinear outline the single-valued influence lines and separately loaded parts of two-valued influence lines with coefficient of distortion ψ ≥ 1.10 and length λ ≥ 2 m are loaded according to i.2* of the present Appendix taking into account the following instructions. a) at 1.10 ≤ ψ ≤1.40 (except the case when the track is arranged on the ballast and λ < 50 m) with increasing the intensity of the equivalent load to the value , % , equal to e (ψ - 1), where e is the coefficient determined by Dwg. 1. when the track is arranged on the ballast and λ < 50 m, the value v shall be taken as per Table 1, at this, for λ ≤ 10 m not depending on influence line top position - as per column corresponding to α=0.5. b) when ψ > 1.40 it is necessary to sum from loading the parts of influence line. Top included part of the influence line of length λ1 and area A1 (dwg.2), bordered by ordinates y1 and y2 is loaded for maximum (in accordance with λ1 and α1); the other part of influence line (A – A1) is loaded with the load 9.81K kN/m (K tf/m) of track. At this the force summed value shall be specified not less than v (A1+A2), where v is determined in accordance with λ1 and α1 of the whole line of influence. The length λ1 see (Dwg.2) shall be specified taking into consideration the design diagram of the structure. Dwg. 2. Part of the influence line of length λ1 including its top 5. Forces (of considered sign) in the lines of influence consisting of several parts shall be determined by the total of results of loading the separate closely located parts of the whole influence line or part of it. According to outlines of influence lines and meaning of values λ and α for parts it should be loaded: two parts of considered sign, located close or separated by part of the other sign, with total length of these (two or three) parts less than 80 m; one part of considered sign with length of 80 m and more; other parts of the same sign are loaded with the load 9.81K kN/m (K tf/m) of track. Separating parts of other sign shall be loaded with the load 13.73 kN/m (1.4 tf/m) of track, and in availability of such parts up to 20 m long one of them is not loaded. Examples of some loadings are shown in Dwg.3 and 4. Dwg.3. Diagram of loading the parts of the line of influence at λ > 80 m Dwg.4. Diagram of loading the span simultaneously with the sliding triangle or the span with abutment when designed the solid abutments of bridges with simple span structures. 6*. When designed the solid abutments of bridges with simple span structures the loading of the span simultaneously with the sliding triangle or the span with abutment shall be carried out according to Dwg. 4 and Table 2. The sliding triangle length shall be specified equal to half height from foot of sleepers to considered section of pier.

T a b l e 2 Diagram Loaded part Length of Accepted Equivalent of

of of bridge loaded Limitations position of Load, kN/m loading parts, m Influence (tf/m) of track (Dwg.4) Line top α Span λ1 0* v1

α Abutment λ2 ≤ 20 λ = λ1+λ2+λ3 ≤ 80 - 0 Siding triangle λ3 0.5 v3≤19.62K(2K)

SNiP 2.05.03-84 Page 160

Span λ1 0 v1 б1 Abutment λ2 ≤ 20 λ = λ1+λ2+λ3 ≥ 80 - 0 Sliding triangle λ3 - v3≤9.81K(K) Span λ1 - v3≤9.81K(K) б2 Abutment λ2 ≤ 20 λ = λ1+λ2+λ3 ≥ 80 - 0 Sliding triangle λ3 0.5 v3 В Span λ1 0 v1 Abutment λ2 λ1+λ2 ≤ 80 0.5 V2≤19.62K(2K) г1 Span λ1 0 v1 Abutment λ2 λ1+λ2 ≥ 80 - v2=9.81K(K) г2 Span λ1 - v2=9.81K(K)

Abutment λ2 λ1+λ2 ≥ 80 0.5 v2 _________________

In case of the ballast way λ1 < 25 m it shall be specified α = 0.5 (see item 2). The load safety factor shall be taken following the reduced length of loading equal to the total of lengths of parts where in each case

the live load is loaded. 7. When loaded the span structures located on curves the load value v shall be taken with the coefficient representing the

influence of displacement of the moving train gravity centre, at this, the calculation shall be carried out two times: a) taking into consideration the centrifugal force and dynamic coefficient but not accounting the force factors

originating due to superelevation of the external radius; b) not taking into consideration the centrifugal force and dynamic coefficient but with accounting the force factors originating due to

superelevation of external radius. 8. When computed the endurance the maximum and minimum forces (stresses) in the lines of influence indicated in the item 5 determinated by the unfavorable from loadings originating from the moving train and consisting of the load εCK (that loads

only one part) and the load 9.81K kN/m (K tf/m) of track. Loading is carried out in series by parts of the line of influence - separately from the right to the left and from the left to the right (Dwg.5). With symmetrical line of influence the loading is carried out in one

direction. Dwg. 5. Diagram of loading the parts of line of influence for determination of maximum and minimum forces (stresses) when designed the endurance.

APPENDIX 6

For reference

EQUIVALENT LOADS FROM SINGLE HEAVY LOADS HK-80 AND НГ-60 Table 1

Length of loading λ, m Equivalent loads, kgf/m (tf/m), at different positions of triangular influence line vertex

7.27. HK-80 НГ-60 middle and quarter end any point

4 176.5 (18.00) 215.7 (22.00) 117.7 (12.00) 5 163.2 (16.64) 200.8 (20.48) 117.7 (12.00) 6 156.9 (16.20) 183.1 (18.67) 114.4 (1167) 7 147.3 (15.02) 166.6 (16.99) 108.1 (11.02) 8 137.3 (14.00) 152.0 (15.50) 101.1 (10.31) 9 127.9 (13.04) 139.5 (14.22) 94.4 (9.63) 10 119.2 (12.16) 128.7 (13.12) 88.3 (9.00) 11 111.5 (11.37) 119.3 (12.17) 82.7 (8.43) 12 104.6 (10.67) 111.1 (11.33) 77.7 (7.92) 13 98.46 (10.04) 104.0 (10.60) 73.1 (7.45)

SNiP 2.05.03-84 Page 161

14 92.87 (9.47) 97.7 (9.96) 69.0 (7.04) 15 87.87 (8.96) 92.1 (9.39) 65.4 (6.67) 16 83.36 (8.50) 87.1 (8.88) 62.1 (6.33) 18 75.51 (7.70) 78.4 (8.00) 56.3 (5.74) 20 69.04 (7.04) 71.4 (7.28) 51.5 (5.25) 22 63.55 (6.48) 65.5 (6.68) 47.4 (4.83) 24 58.84 (6.0) 60.5 (6.17) 43.9 (4.48) 26 54.82 (5.59) 56.2 (5.73) 40.9 (4.17) 28 51.19 (5.22) 52.5 (5.35) 38.2 (3.90) 30 48.15 (4.91) 49.1 (5.01) 36.0 (3.67) 32 45.31 (4.62) 46.3 (4.72) 33.9 (3.46) 36 40.70 (4.15) 41.4 (4.22) 30.4 (3.10) 40 36.87 (3.76) 37.5 (3.82) 27.6 (2.81) 50 29.91 (3.05) 30.2 (3.08) 22.4 (2.28) 60 25.11 (2.56) 25.4 (2.59) 18.8 (1.92) 70 21.67 (2.21) 21.9 (2.23) 16.2 (1.65) 80 19.02 (1.94) 19.2 (1.96) 14.2 (1.45)

Note. Equivalent loads are determined by the following formulae: for wheel load HK-80

at 0 ≤ α ≤ 0.25

b) at 0.25 < α ≤ 0.50

for crawler load НГ-60

Table 2* Length

Equivalent loading , kN/m (tf/m), for curvilinear lines of influence (with different distortion coefficients ψ* ) for loads

НК-80 НГ-60 НК-80 НГ-60

ψ=0.75-0.85 ψ =1.05-1.25 ψ =- 1,30— 1,50

ψ =1,1-1.2 ψ =.05—1,25

ψ =1.3-1.50

Length of loading λ, m

4 159 (16,2) 118 (12,0) 182 (18,6) 190 (19,4) 225 (22,9) 118 (12,0) 118 (12,0) 5 158 (16,1) 118 (12,0) 170 (17,3) 175 (17,8) 210 (21,4) 118 (12,0) 118 (12,0) 6 157 (16,0) 114 (11,6) 162 (16,5) 171 (17,4) 191 (19,5) 116 (11,8) 117 (11,9) 7 145 (14,8) 108 (11,0) 153 (15,6) 165 (16,8) 177 (18,1) 111 (11,3) 113 (11,5) 8 130 (13,3) 102 (10,4) 144 (14,7) 158 (16,1) 163 (16,6) 105 (10,7) 109 (11.1) 9 121 (12.3) 93 (9,5) 135 (13,8) 150 (15,3) 151 (15,4) 99 (10,1) 105 (10,7)

10 112 (11,4) 86 (8,8) 127 (13,0) 140 (14,3) 140 (14,3) 94 (9,6) 100 (10,2) 12 97 (9,9) 73 (7,4) 110 (11,2) 127 (12,9) 123 (12,5) 83 (8,5) 90 (9,2) 14 85 (8,7) 65 (6,6) 101 (10,3) 114 (11,6) 109 (11,1) 76 (7.7) 77 (7.9) 16 75 (7.6) 56 (5,7) 92 (9,4) 104 (10,6) 97 (9.9) 69 (7,0) 76 (7,8) 18 67 (6,8) 50 (5,1) 83 (8,5) 95 (9,7) 87 (8,9) 62 (6,3) 72 (7.3) 20 61 (6,2) 45 (4,6) 76 (7,8) 88 (9.0) 81 (8,3) 57 (5,8) 68 (6,9) 22 56 (5,7) 42 (4,3) 70 (7,1) 81 (8,3) 74 (7,5) 53 (5,4) 59 (6,0)

;)1

8.1(15692 α

λλ

ν−

−=

;])1(

3.01

6.0[15692 ααα

λλ

ν−

−−

−=

;)5.2(11772 −= λ

λν

SNiP 2.05.03-84 Page 162

24 51 (5,2) 38 (3,9) 66 (6,7) 76 (7,7) 69 (7,0) 49 (5.0) 56 (5,7) 26 47 (4,8) 35 (3,6) 62 (6,3) 71 (7,2) 64 (6,5) 46 (4,7) 54 (5.5) 28 44 (4,5) 32 (3,3) 58 (5,9) 67 (6,8) 60 (6,1) 43 (4,4) 49 (5,0) 30 41 (4,2) 30 (3,1) 54 (5,5) 64 (6,5) 56 (5,7) 41 (4,2) 47 (4.8) 32 38 (3,9) 28 (2,9) 52 (5,3) 60 (6,1) 53 (5.4) 38 (3,9) 44 (4,5) 36 34 (3,5) 25 (2,6) 46 (4,7) 54 (5,5) 47 (4,8) 34 (3,5) 40 (4,1) 40 31 (3,2) 24 (2,4) 42 (4.3) 49 (5,0) 43 (4.4) 31 (3,2) 36 (3,7)

*Distortion coefficient ψ equals to ratio of triangular influence line area to area of line of influence under consideration at equal lengths of lines of influence and equal their maximum coordinates.

For intermediate values the coefficient ψ shall be determined by interpolation.

APPENDIX 7

For reference

EQUIVALENT LOADS FROM SINGLE CARS, STANDING AND MOVING TRAINS OF CARS OF LOAD АБ

Equivalent loads from loads АБ at different positions of vertexes of trigonal lines of influence, kN/m (tf/m) АБ-51 А6-74 АБ-151

Length of

loadingλ, m α =о,5 α = 0,25 α =о α =0,5 α = 0.25 α =0 " =0,5 о = 0,25 а=о .

А. Single car 4 166,7

(17,00) 166.7

(17,00) 177,1

(18,06) 245,2

(25.00) 245,2(25,0

0) 245,2

(25,00) 495,2

(50.50) -495,2 (50,50)

495.2 (50,50) 5 133,4 137,8 153,4 186,1 196,1 211.2(21,5 396.2 396.2 415.8

В 111,1 123,5 134,3 163.5(16,6 168.7 187,0 330,2 330,2 371,0(37,837 95,2 (9,71) 111,1 119,1 140.1 153,6 167,0 283,0(28,86) 303,0 333,0 8 88,6 (9.03) 100.7 106,8 122.6 140,2 150,5 247,6 278,3 301,3(30.729 82.4 (8,40) 91,9(9,37) 96,7 (9,86) 112,5(11,4 128.8(13,1 136,9 220,1 256.4(26,15 274.6

10 76,7 (7,82) 84,4 (8,61) 88,4(9,01) 105,6(10.7 118,8 125.3(12,7 207.9(21.20) 237,3 252.0 12 67,2 (6,85) 72,6 (7.40) 75,2 (7,67) 93,5 (9,53) 102,7 107,2 185,5(18,92) 205,9(21,00 216.1 15 56,3 (5.74) 59.7(6,09) 61,5(6,27) 79,2 (8,08) 85.0 (8.67) 88,0 (8,97) 158,2 171,3 177.8 18 48,3 (4,93) 50,8 (5,18) 52,0 (5,30) 68,4 (6,98) 72,5 (7,39) 74,5 (7,60) 137,3 146,4 150.9 24 37,7 (3,84) 38.9 (3,97) 39,6 (4.04) 53,6 (5,47) 55,9 (5,70) 57,1 (5,82) 108,1 113,2 115,7(11,8030 30.8 (3,14) 31,6 (3,22) 32,1 (3,27) 44,0 (4,49) 45,4 (4,63) 46,2 (4.71) 88,9 (9,07) 92,2 (9,40) 93,8 (9.57) 33 28,1 (2,87) 28.8 (2,94) 29,2 (2,98) 40,3 (4.11) 41,6 (4,24) 42,2 (4,30) 81,7 (8,33) 84,3 (8,60) 85,7 (8.74) 36 26,0 (2.65) 26,6(2,71) 26,9 (2,74) 37.3 (3,80) 38,2 (3,90) 38.8 (3,96) 75.4 (7,69) 77,8 (7,93) 78.8 (8,04) 48 19,8 (2,02) 20,2 (2,06) 20,3 (2,07) 28.5 (2,91) 29,1 (2,97) 29,4 (3.00) 57,9 (5,90) 59.1 (6.03) 59,8 (6,10) 66 14,6 (1,49) 14,8(1.51) 14,9 (1,52) 21,1 (2,15) 21,4(2,18) 21,6 (2,20) 42,9 (4,37) 43.5 (4,44) 43,8 (4,47)

Б. Standing cars train 10 76.7 (7,82) 84.4 (8,61 88,4 (9,01) 105,6

(10,77 118,8

(12.11) 125,3

(12,78) 207.9(21,20) •237,3

(24,20) 252,0

(25,70) 12 67,2 (6.85) 72,6 (7.40) 77,6(7.91) 93,5 (9.53) 102,7 107,2 185,5 205,9 216,1 15 56.3 (5,74) 59.7 (6,09) 71,9 (7,33) 79,2 (8,08) 85,0 (8,67) 100,2 158,2(16,13) 171,3(17.47 182,2(18.5818 50,4 (5,14) 56.3 (5,74) 68,5 (6.98) 71,3(7,27) 77,8 (7,93) 94.4 (9,63) 137,3 146,4 172.3(17.5724 44,6 (4,55) 51.3 (5,23) 60,5 (6.17) 60,1 (6,13) 70.8 (7,22) 83,4 (8.50) 114,9(11.72) 129,3 156.9(16.0030 46,3 (4,72) 47.7 (4,86) 57,8 (5.89) 63,5 (6,48) 66.3 (6.76) 79,5(8,11) 102,0(10,40) 120,7(12,31 142.1 33 46,6 (4,75) 47,3(4,82) 56,0 (5.71) 63.3 (6,45) 64,5 (6.58) 77,8 (7.93 107.9(11,00) 116.4(11.87 139,3 36 46,1 (4,70) 46,7 (4,76 54,0 (5,51) 63,3 (6,45) 64.2 (6,55) 75,4 (7,69 108.9 (11,11 113,8 137,2 48 41,6 (4,24) 41,9(4.27) 46,0 (4,69) 58.3 (5,94) 58,8 (6.00) 65,1 (6,64) 106.7 108,0 123,5 ВО 34.3 (3,50) 34.5 (3,52) 36,8 (3,75) 48,8 (4,98) 49,1 (5,01) 52,5 (5,35) 93.2 (9,50) 93,8 (9,57) 102,0

В. Moving cars train 18 48,3 (4.93) 50,8 (5,18) 52,0 (5,30) 68,4 (6.98) 72,5 (7,39) 74,5 (7,60) 137,3

(14.00) 146.4(14,93

) 151,0

(15,40) 24 37.7 (3,84) 38,9 (3.97) 40,2 (4,10) 53,6 (5,47) 55,9 (5,70) 57,1 (5,82) 108,1 113.2(11,54 115,8 30 30,8 (3,14) 31,6(3,22) 38,0 (3,87) 44,0 (4,49) 45,4 (4.63) 53,3 (5,44) 88,9 (9,07) 92,3(9.41) 93,8 (9,57) 33 28,1 (2,87) 29,9 (3.05) 36.9 (3,76) 40,3 (4,11) 42,3 (4,31) 52,1 (5,31) 81.7(8,33) 84,4 (8,61) 90.2 (9,20) 36 26,0 (2.65) 29,0 (2,96) 35,6 (3,63) 37,3 (3,80) 41.1 (4.19) 50,5 (5,15) 75.4 (7.69) 77,8 (7,93) 88.1 (В.98 48 21,6(2,20) 26,8 (2.73) 30,8 (3,14) 30,2 (3,08) 37,9 (3.86) 43,5 (4,44) 57.9 (5,90) 66,2 (6,75) 80.3 (8,19) 66 23,3 (2,38) 23,5 (2,40) 28,4 (2,90) 32,9 (3,35) 33.1 (3,38) 40,4(4,12) 50.5 (5,15) 59,4 (6,06) 69.3 (7,07)

Note. Intermediate values of equivalent loads shall be determined by interpolation

SNiP 2.05.03-84 Page 163

APPENDIX 8

Compulsory

METHODS OF DETERMINING HORIZONTAL (LATERAL) EARTH PRESSURE AGAINST LAND PIERS (ABUTMENTS) FROM RAILWAY AND HIGHWAY

MOVING VEHICLES I. When the railway moving train is on the sliding triangle

Horizontal (lateral) pressure , kN (tf), shall be determined as follows: for one-track abutment at symmetrical (relative to abutment axis) load (Dwg.a)

for multi-track abutment at nonsymmetrical (relative to abutment axis) load (Dwg. b)

If h2 =h, then it is taken α2=α. The arms of forces F1, F2, F3, and F4 , counting from section under consideration (on Dwg - footing of foundation) shall be

determined by the following formulae.

Where

- pressure of live vertical load distributed at length of sleepers (2.70), kPa (tf/m2);

v - equally distributed load, kN (tf/m), from moving train on the

)1(;)(7.2 11121 haahbphpFFF nn −+=+= ττ νν

)2();(5.035.1)(5.035.1

2212

1114321

haahbphphaahbphpFFFFF

nn

nn

−+++−+=+++=

ττττ

νν

νν

;22

3hhz −=

;)(

11

111112

2 αα

ξαξα

hhhhhhh

z−

−+−=

.)(

22

222222

4 ααξαξα

hhhhhhhz

−−+−

=

;2

23

hhz −=

70.2vpv =

SNiP 2.05.03-84 Page 164

sliding triangle (as per Appendix 5*, compulsory); h1, h2 - height within that the pressure area has variable width, m; b - width of one-track abutment or doubled minimum distance

from vertical axis of load to nearest side face of abutment at nonsymmetrical loading, m;

b1=2.70+h2 - doubled distance from axis of track to point of crossing the line

of distributing the load of side face remoted from the track , m, but not more than doubled maximum distance from track axis

to side face of abutment; τn - coefficient of rated horizontal (lateral) pressure of filling earth

as per the item 2.6.

Diagram of loading to determine horizontal (lateral) earth pressure to land piers (abutments)*: α) when railway moving train is located on the sliding triangle for one-track abutment at symmetrical (relative to axis of abutment)

load; б) ditto, for multi-track abutments at nonsymmetrical (relative to axis of abutment) load ;

в) when located on the sliding triangular the wheeled and tracked vehicle loads and wall perpendicular to traffic direction (c – length of touching the wheels or track with roadway surface axially the bridge). On diagram of loading to the angle the value β means

inclination to vertical plane of earth sliding behind abutment. The values of coefficients α,α1, α2, and ξ, ξ1, ξ2 in dependence upon relevant heights h, h1, h2 shall be taken by Table 1.

Note. For multi-track abutment the general pressure from live load shall be determined as the total of pressures produced by formula (2) for each of tracks separately at relevant values b, b1, h, h1, h2.

Table 1 h, h1, h2 α,α1, α2 ξ, ξ1, ξ2 h, h1, h2 α,α1, α2 ξ, ξ1, ξ2

1 0.85 0.53 16 0.33 0.65 2 0.75 0.55 17 0.32 0.66 3 0.67 0.56 18 0.31 0.66 4 0.61 0.58 19 0.30 0.66 5 0.57 0.59 20 0.29 0.67 6 0.53 0.60 21 0.28 0.67 7 0.49 0.60 22 0.27 0.67 8 0.46 0.61 23 0.27 0.67 9 0.44 0.62 24 0.26 0.68

10 0.42 0.62 25 0.25 0.68 11 0.40 0.63 26 0.25 0.68 12 0.38 0.64 27 0.24 0.68 13 0.37 0.64 28 0.23 0.69 14 0.35 0.64 29 0.23 0.69 15 0.34 0.65 30 0.22 0.69

II. When the wheeled or tracked vehicle loads are on the sliding triangle 1*. In absence of embankment-to-abutment transition slabs the pressure from highway vehicles being on the sliding triangle shall be

specified as distributed to the areas of contact. A. When the wall is positioned perpendicular to traffic direction the pressure from each row of wheels or track is distributed to areas of

contact c x b , where c – length of touching the wheels or track of loads under consideration with

roadway surface axially the bridge (drawing , в), specified in m: for cart wheels of load AK – 02;

for car wheels of load АБ - as per Table 10, item 2.13;

SNiP 2.05.03-84 Page 165

for wheeled load HK-80 - 3.8; for tracked load НГ-60 - 5.0;

b - width equal to a distance between outer faces of wheels (for cart of load AK, cars of load АБ, wheeled loads HK-80) or track (for tracked load НГ-

60). In cases when concentrated pressure is distributed to the sides lengthwise the wall under computation (for ex. Abutments with sloped

wings), it is specified with the coefficient α, depending on ratio b/h (where h is a height of wall ), as per Table 2. In U-shaped abutments in parallel to the bridge axis the coefficient α is ignored.

Table 2 b / h α b / h α 0.10 0.327 0.60 0.681 0.12 0.360 0.70 0.710 0.14 0.389 0.80 0.735 0.16 0.414 0.90 0.754 0.18 0.437 1.00 0.772 0.20 0.459 1.20 0.810 0.25 0.505 1.50 0.840 0.30 0.544 2.00 0.875 0.35 0.576 3.00 0.900 0.40 0.602 4.00 0.950 0.50 0.668 above 4.00 1.000

B. When the wall is positioned in parallel to the bridge axis the pressure from each row of wheels lengthwise the bridge and from each track line is distributed onto the areas of contact of size α x d.

Where α - length specified for loadings, m; AK – h + 1.5;

АБ - h + c, but not more than axle base of a motor vehicle; HK–80 - 3.8;

НГ-60 - 5.0; h, c – as per sub-item A;

d - width of wheel or track of loads under consideration. In all cases the length α should not exceed the length the considered part of wall.

2. In availability of transition slabs (from embankment to abutment) the rest onto the earth (axially the bridge) shall be taken into account on a half of slab length from the side of embankment, at this the pressure shall be specified only from the part of live load

located on this half, and considered as to apply in the middle of length of rest.

APPENDIX 9*

Compulsory

AERODYNAMIC COEFFICIENT Parts and members of span structures and piers of bridge

Head resistance aerodynamic coefficient, cw

Parts and members of span structures and piers of bridge

Head resistance aerodynamic coefficient, cw

1. Main trusses of through span structures of beam and arc systems:

6. Stone, concrete and reinforced concrete of bridges:a) across the bridge

SNiP 2.05.03-84 Page 166

a) railway through bridge with train on it

2.15

rectangular section ditto, but with fairing in nose and

2.10

no train on it 2.55 stern parts 1.75 Railway deck-type bridge with distance between truss axes from 2 to 4 m, respectively

2.15-2.45

round section in form of two round cylinders b) along bridge with rectangular section

1.40

1.80

2.10 b) highway bridges

2.80 7. Timber through

piers of bridges:

a) tower-type: 2. Grid of beams and across the bridge 3.20 deck of roadway of span structures:

along the bridge b) one-row and twin:

2.40

a) railway 1.85 across the bridge 2.50 b) highway 1.60 along the bridge 1.50 3. Superstructures 8. Steel piers: with continuous beams:

one-row:across the bridge

2.50

a) railway : along the bridge 1.80 single-track, deck- -type

1.90

b) tower-type through with number

two single-track, deck-type, mounted on common piers of two-track bridge

2.10

of planes (across the wind direction) 2-4 9. Hand railings:

2.10-3.00

single-track in form of locked box

1.50

a) in deck-type bridges for planes:

single-track, through span

2.25

unprotected against the wind

1.4

two-track, through span

2.45

closed against the wind with moving vehicles

0.8 b) highway deck-type: b) in through bridges: with flat main girders 1.70 from windward side, with one box-type beam

1.50

not closed with partsof through trusses

1.4

with two box-type beams

1.75

ditto, close with parts of through trusses

1.1

ditto, closed with 4. Stringers 1.95 parts of through

trusses and moving

5. Railway moving train being on:

vehicles

a) through span 1.50

SNiP 2.05.03-84 Page 167 b) deck-type span 1.80 Note. For piers consisting of several tiers as per height, having different forms in design, the wind load shall be determined individually for each tier taking into account the corresponding aerodynamic coefficient.

APPENDIX 10*

Compulsory

CHARACTERISTIC ICE FORCES 1. Ice forces on piers shall be determined on the base of initial data on ice condition at site of bridge location for period of maximum

ice action, at this the period of field observations should be not less than 5 years. Strength limits of ice shall be determined by the experience data.

If experience data are not available it is allowed to specify as follows: for region I of the country :

Crushing strength limit of ice (including the local bearing stress) Rz1: when ice drift begins (during the first debacle) – 735 kPa (75 tf/m2);

at maximum ice drift line – 441 kPa (45 tf/m2); flexural strength limit of ice Rm1 – 70% of corresponding values of

crushing strengh of ice (as per sub-point “a”); for other regions of the country – as per formulae:

Rzn = Kn Rz1 ; (1) Rmn = 0.7 Rzn ; (2)

Where n – serial number of country region; Kn – climatic coefficient for the given region of the country.

The boundary of regions and corresponding climatic coefficients shall be specified as per Table 1. At this, for the rivers with debacle at negative temperature the climatic coefficient shall be specified not less than 2.

On fully frozen rivers if debacle drift begins after spring water passing above ice , the crushing strength limit of ice shall be taken as per actual data (taking into account ice weakening due to its thawing, but not less than values installed for ice drift with the maximum

line. 2. The resultant of ice force shall be applied in the point located beneath the water stage for 0.3 t, where t is designed thickness of ice,

m, taken equal to 0.8 of maximum probability of winter thickness of ice. 3. Forces from moving ice fields on bridge piers with a vertical front face shall be specified as per least value among determined by

formulae: F1 = ψ1 Rzn bt , kN (tf) ; (3) when the pier stops the ice field

where ψ1, ψ2 - coefficients of shape determined as per Table 2. Rzn - crushing strength of ice for regins of construction , kPa (tf/m2);

b - width of pier at a level of ice action, m; t - thickness of ice, m;

v - speed of ice field flow, m/s, determined by the data of field observations, and specified equal to water flow speed in case the data are not available.

A - area of ice field, m2, installed by field observations in place of bridge crossing or close to it. Table 1

Number of region Boundary of region Climatic coefficient Kn

)4(},,4.0(

,253.1

22

22

tfARvtF

kNARvtF

zn

zn

ψ

ψ

=

=

SNiP 2.05.03-84 Page 168

I Southward of line Vyborg-smolensk-Kamyshin-Aktuybinsk-Balkhash

1

II Southward of line Arkhangelsk-Kirov-Ufha-Koustanai-Karaganda-Ust-Kamenogorsk

1.25

III Southward of line Vorkuta-KhantyMansiysk – Krashoyarsk-UlanUde-Nikolayevsk-on-Amur

1.75

IV Northward of line Vorkuta-KhantyMansiysk – Krashoyarsk-UlanUde-Nikolayevsk-on-Amur

1.75

Note. For regions II and III the south boundary is the north boundary of preceding region. Table 2

Coefficient of shape for piers with noze part, havin in plan the shape of Coeffici- poligon rectangle triangle with tapering angle in plan, grad. ent 45 60 75 90 120 150 ψ1 0.90 1.00 0.54 0.59 0.64 0.69 0.77 1.00 ψ2 2.4 2.7 0.2 0.5 0.8 1.0 1.3 2.7

If field data are not available the ice field area can be taken as A= 1.75 l2, where l – value of span in m, and in case of water surface slopes i ≥ 0.007 A = 1.02 tRmn

(A = 10tRmn), } (5) where Rmn – flexural strength limit of ice in region of construction, kPa (tf/m2).

4. When ice field moves at an angle ≤ 80° with the bridge axis the load from ice to the pier vertical face shall be decreased by means of multiplying of it by sin ϕ.

5. Ice pressure against the pier having the incline plane in zone of ice action shall be determined as follows: a) horizontal component Fx , kN (tf) – as per the least among values produced by the formula (3) of the present appendix and by the

formula:

b) vertical component Fz , kN (tf) – as per formula:

where ψ - coefficient taken equal to 0.2 b/t, but not less than 1; β - angle of incline to horizon of the pier cutting rib.

Rmn, b, t - are taken as per items 1-3. 6*. In complicated ice situation in the region under construction of the bridge crossing it should be considered in necessary cases the

loads from: ice field stopped as a result of impact against the pier, when besides water

flow the field is attacked by the wind; pressure of ice dam;

ice cover on pier (piles or pile cluster) produced by water level fluctuation; ice cover during its temperature expansion and availability from one side of support

7*. On location of two piers of round outlines or close to round outlines (drawing above) in one section line along water current the pressure of bypass channel during the first debacle onto downstream (the second) pier can be taken in size æF1 ,

where æ – coefficient of reducing the pressure to downstream (the second) pier,

)6(;2 βψ tgtRF mnx =

)7(,βtg

FF xz =

SNiP 2.05.03-84 Page 169

depending on ratio α0/D (α0 is a distance between pier axes, D is pier diameter);

F1 – pressure of bypass channel onto upstream (the first) pier (item 3). Coefficient value æ shall be taken by Table 3*.

Table 3* α0/D 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8

æ 0.200 0.204 0.212 0.230 0.380 0.398 0.472 0.542 0.608 α0/D 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 and more

æ 0.671 0.730 0.785 0.836 0.884 0.928 0.968 1 Note. Intermediate values are determined by interpolation.

APPENDIX 11*

Compulsory

LOSSES OF PRESTRESS IN REINFORCEMENT Table 1*

Reason for losses of pre-stress in reinforcement

Values of pre-stress losses

1. Reinforcement stress relaxation a) at mechanical method of tension - wire reinforcement - bar reinforcement b) at electrothermal and electrothermal- and-mechanical methods of bar reinforcement tension

0.1 σp – 20 0.03 σp Here σp is taken not considering the

losses, MPa. If calculated values of losses from stress relaxatiom are negative, they should be taken equal to zero.

2. Temperature drop at pretensioning (temperature difference between tensioned reinforcement in heat zone and device receiving the tension force during warm-up of concrete)

For concrete of class B25-B40 - 1.25 ∆t, ditto class B45 and high - 1.0 ∆t, where ∆t – temperature difference between reinforcement under heating and fixed stops (beyond the heating zone), receiving the tension force, C°

Design value ∆t in absence of exact data shall be taken equal to 65°C. Temperature drop losses are ignored if temperature of

pph

p

Rσ

σ)1.022.0( −

SNiP 2.05.03-84 Page 170

the stand is equal to temperature of reinforcement under heating or if the thermal treatment includes additional tension of stressed reinforcement by value of temperature drop losses compensation

3. Deformation of anchors located near tension devices , when tensioning a) against stops

where ∆l - compression of molded washers, bearing strain of formed heads, etc. taken equal to 2 mm for each anchor

where ∆l1 - compression of washers under anchors and pressing down the concrete under washers equalled to 0.5 mm for each joint but not less than 2 mm for each anchor where tension takes place. ∆l2 - deformation of reinforcing member relative to anchor taken equal to:

- 2 mm per anchor for sleeve- type anchor to which wire is

fastened with a help of alloy, concrete, cone fixing, formed heads;

- 1 mm per anchor for stressed stirrups; - 8 mm per anchor for cone

anchors of tendons of strands, class K-7; - for bar stirrups with tightly screwed nuts and washers or paired short bars the total of

losses of all kinds in such stirrups can be considered in value

98MPa (1000 kgf/cm2); l – length of reinforcing member under

tension, mm; Ep – modulus of elasticity of stressed

reinforcement 4. Friction of reinforcement

,pEll∆

,21

pEl

ll ∆+∆

SNiP 2.05.03-84 Page 171 a) against walls of closed and open ducts during post tensioning

Where σp - is taken not considering loss e – base of natural logarithms ω, δ - coefficients specified by Table 2*

of present appendix; x - length from tension device to design

section , m; ⊕ - total angle of turning for axis of

reinforcing bar, rad. b) against bending devices

Where σp - is taken not considering loss e – base of natural logarithms

δ - coefficient specified equal to 0.25 ⊕ - total angle of turning for axis of

reinforcing bar, rad. When using intermediate deflecting stop

devices, separately for each reinforcing bar and having movement (by means of turning) along the wall the losses of friction against stop devices can be ignored.

5. Deformation of steel form during manufacturing prestressed reinforced concrete structures with tension against stops

Where η - coefficient that is determined by the following formula, when reinforcing bars are tensioned by jack

∆l – convergence of stops on line of prestress force action, determined by deformations of form;

l – distance between outer faces of stops; n – number of reinforcing bar groups

( )⊕+−= δωσ xh e11

( )⊕

−=δ

σeh

11

,sEll∆

η

;2

1n

n −η

SNiP 2.05.03-84 Page 172

tensioned insimultaneously; Es – modulus of elasticity for steel of

form. If data on fabrication and structure of

form are not available then form deformation losses shall be specified equal to 30 MPa

6. Fast creep during pretensioning : a) concrete of natural hardening

b) concrete subjected to heating

Where σbp is determined at a level of gravity centres of relative longitudinal reinforcement taking into account the losses as per items 1-5 of the present Table.

7. Shrinkage of concrete Concrete classified as per compressive strength

a) during pretensioning B35 and less

B40 B45 and less

Concrete of natural hardening 40 50 60 Concrete subjected to heating 35 40 50 b) concrete independent on hardening conditions

30

35

40 8. Creep of concrete

where σbp – ditto as in item 6 of the present Table, but taking into account the losses as per items 1-6; Rbp – transmission strength (see item 3.31*); α - coefficient taken equal to

) ,8.08.0(9432

;8.040

>−+

≤

δρ

δρ

δρ

δρ

δρ

δρ

δρ

δρ

σσ

σσ

Rat

R

Rat

R

) 75.0375.0(300

;75.0150

>−

≤

δρ

δρ

δρ

δρ

δρ

δρ

δρ

δρ

σσ

σσ

Rat

Ra

Rat

Ra

SNiP 2.05.03-84 Page 173

1.0 for concrete of natural hardening and 0.85 for concrete subjected to heating

at atmospheric pressure. 9. Bearing stress of turns of spiral or hooped reinforcement wound on concrete, (when diameter of structure dext up to 3 m)

70 – 0.22 d ext

10. Deformation of compressing of butt joints between blocks (for structures consisting of blocks )

Where n – number of joints and accessories on length of reinforcement under tension; ∆l - compressing of butt specified as follows: 0.3 mm for butts filled with concrete;

0.0 for butts glued after glue hardening; l - length of tensioned reinforcement.

Deformation of butt joints can be determined with other methods base on experience data.

Note. Each kind of losses of pretensioning the reinforcement according to item numbers shall be assigned with designation from σ1 to

σ10

Table 2*

Coefficients for determination of losses from reinforcement friction (see item 4 of Table 1*)

δ when reinforcement in form of

Surface of duct

ω

tendons of high-tensioned wires, strands of class K-7, steel wire ropes and plain bars

deformed bars

Plain steel 0.003 0.35 0.4 Concrete formed with help of rigid duct former

(or polyethilene pipes) 0.005 0.55 0.65

Corrugated polypropilene 0.20 0.20 -

Table 3 Values of characteristic deformations of creep cn and shrinkage εsn for concrete of classes as

,sEl

ln∆

SNiP 2.05.03-84 Page 174

per compressive strength Index B20 B22.5 B25 B27.5 B30 B35 B40 B45 B50 B55 B60

cn 106, MPa-1 115 107 100 92 84 75 67 55* 50* 41** 39**

cn 106, kgf-1/cm2 11.3 10.9 10.2 9.4 8.6 7.7 6.8 5.6* 5.1* 4.2** 4.0**

εsn 106 400 400 400 400 400 400 400 365* 330* 316** 300**

With slump of cone 1-2 cm ** With hardness of concrete 35-30 s

Notes. 1. When determining cn and εsn , classes of concrete shall correspond to transferable

strength of concrete Rbψ (refer to i. 3.31). Values cn and εsn shall be decreased by 10% for concrete subjected to moist-steam curing.

APPENDIX 12

Compulsory

DESIGN OF RIGID LINKS OF ROUND REINFORCED CONCRETE PIPES Rigid links of round reinforced concrete pipes can be designed for bending moments (not taking into account normal and cross forces)

which design variables shall be determined by formula where rd - mean radiius of link, m;

p – design pressure taken equal to :

for railway pipes

1.3 (pvp + pvk);

for highway pipes

1.3 pvp + 1.2 pvk ; pvp - characteristic vertical pressure of embankment soil taken as per i.2.6;

pvk - characteristic vertical pressure from live vertical load taken as per i. 2.17;

here ϕn – characteristic angle of inner friction of filling soil; δ - coefficient taken depending on conditions of supporting the link

against foundation or ground (graded) packed cushion according to the Table.

Link Condition of supporting Coefficient δ

,)1(2 δµ−= prM d

,)2

45(2 ntg ϕµ −°=

SNiP 2.05.03-84 Page 175

Round Round with flat abutment

Onto ground (graded) packed cushion at α ≥ 90° Onto foundation (concrete, reinforced concrete) through concrete cushion at α ≥ 120° Onto foundation (concrete, reinforced concrete) or onto ground cushion

0.25

0.22

0.22

APPENDIX 13*

Compulsory

DETERMINATION OF SECTION RIGIDITY OF REINFORCED CONCRETE MEMBERS FOR COMPUTING DEFLECTIONS AND TURN ANGLES TAKING

INTO ACCOUNT CREEP OF CONCRETE Section rigidity of prestressed member (entire by length) under long action of prestress B*p or dead load B*g applied in time moments

ti are recommended to determine by the formula

where EbIred - rigidity of equivalent solid section of member; k - coefficient taking into account action of inelastic strain in

concrete during short-time load and taken equal to 0.85; ϕ lim.i = c lim.i E bi - reduced value of concrete ultimate creep characteristic.

When determined deflections and angle of turns under action of live load or short-time dead load (including short time curve from prestress force) in formula (1) the value of ϕ lim.i shall be taken equal to zero, and stiffness B* shall be replaced for B.

Values ϕ lim.i are recommended to calculate by the formulae: When determined rigidity Bp*

When determined rigidity Bg*

where Φti is a function that takes into consideration the dead loaded concrete prestress (compressing) action to ultimate (at t→ ∞ )

value of reinforcement prestress change (refer to i. 3). 3. Determination of components to compute the reduced characteristic of creep for concrete, ϕ lim,i :

Φti is a function that takes into consideration the dead loaded concrete prestress (compressing) action to ultimate (at t→ ∞ )

value of reinforcement prestress change (refer to i.3).

where

)1(,1

*lim,i

redbIkEBϕ+

=

)2(;lim,pl

tii pn µ

ϕΦ

=•

)3(,)1(

)()1()1( 1

lim,pl

pltipltii np

pnppnµ

µµϕϕ

+

−Φ++=

−

)4(,)1()/(

6.15.1

3

3,

βασα

αα

+++

+=Φ serbbi

ti

R

;1

;125; ,

pl

pl

b

serbtiti pn

pnE

Rµ

µξϕβϕξα ===

SNiP 2.05.03-84 Page 176

Ab,Ib - area and inertion moment of concrete part of section relative to gravity centre of the section;

y - distance from centre of gravity for concrete part section to centre of gravity for stressed reinforcement under consideration;

nl - ratio of modulus of elasticity for reinforcement and concrete taken as per i. 3.48*;

Rb,ser, Eb - rated resistance of concrete against axial compression as per Table 23* when designed as per limit states of second group and concrete elasticity modulus value of modulus of elasticity for concrete, MPa, as per Table

28 (to the beginning of the given stage), corresponding to transfer strength of concrete Rbp;

ϕti = cti Eb - characteristic of linear creep of concrete, appeared during the stage under consideration (for time ∆t) ;

cti - concrete creep specific deformation corresponding to set period of exposure under load, it is recommended to be determined by formulae:

where ∆t - time counted since the moment of load application, daily; αm - parameter described concrete creep strain rate (by time) and

taken as per Table 1 of the present appendix. For structures that are used in climatic subregion IVA, keeping SNiP 2.01.01-82 the value αm in summer period (August) shall be

decreased by 35 %, and in winter (February) – it shall be increased by 10 %,; for other months it shall be taken by linear interpolation;

Table 1

Equivalent characteristic of member cross section in cm, (ratio of member cross section area to its perimeter)

2.5 5.0 7.5 10.0 12.5 15.0 20.0 and more

;sec1 2 tionofpartconcreteofsticcharacteriyIAp

b

b −+=

;)2.0

sec(infinf

b

pspps

b

pp

AAA

takenbeshallAAarea

tioncrosswhenorcementrestressedwithorcingreoftcoefficienAA

+=≥

−=

µ

µ

;,

tstagegiventheofbeginningtheatconcreteinstressesoflevelrelativeR serb

bi ∆−σ

)6(;lim, ttcctwith

mitim ∆+

∆=>∆

αα

)5(;)(2

2/1lim,

m

itim

tcctwith

αα

∆=≤∆

SNiP 2.05.03-84 Page 177

Parameters described concrete creep strain rate (by time), αm, daily

55 80 110 135 165 190 250

Table 2*

Structure behavior conditions Characteristic of structure behavior conditions and numerical values of corresponding coefficients

Concrete compression transfer strength in portion of design class of concrete

- 0.5 0.6 0.7 0.8 0.9 1.0 and more

Coefficient ξ1 - 1.7 1.6 1.4 1.25 1.15 1.0

Age of concrete, daily 3 and less

7 28 60 90 180 360

Coefficient ξ2 1 1 1 0.8 0.7 0.6 0.5

Equivalent characteristic of member cross section (refer to Table 1), cm

2.5 5 7.5 10 12.5 15 20and more

Coefficient ξ3 1 0.85 0.76 0.72 0.69 0.67 0.64

Relative humidity of environment *, %

40 and less

50 60 70 80 90 100

Coefficient ξ4 1.33 1.25 1.15 1.0 0.85 0.7 0.51 * Humidity is taken as mean relative air humidity of the most hot month as per SNiP 2.01.01-82, and with location of structures in

subregion IVA it is taken as mean month humidity corresponding to period of compressing the concrete. For mass members with ratio of section area to its perimeter not less than 20 cm, the value ξ4 is taken equal to 0.55. For typical structures it is allowed

to take ξ4 = 1. clim,i - limit values of concrete creep specific strains:

where cn - characteristic value of concrete creep strains, taken according to compulsory appendix 11*.

ξi - the coefficients given in Table 2*.

APPENDIX 14*

Compulsory

COEFFICIENTS OF CABLE WORKING MODE The coefficient of working mode m1 shall be taken :

where D = 2R;

)7(,4321lim, ξξξξni cc =

,)(17.0000125.0264.0 d

D

l edDm

−=

SNiP 2.05.03-84 Page 178

R - radius of curve by which one stranded cable of wire in dia d with ultimate resistance 1470 - 1765 MPa (150-180 kgf/mm2) is bent on the deflection device; at this, condition D/d ≥ 580 and ml ≥ 0.85 shall be

observed. Ml = 1 when closed bearing cables are bent on deflection device by circular curve of diameter D, mm, and the following conditions are observed:

where ds - diameter of cable in mm.

When cross load q acts onto tensile closed bearing cable through flat steel cover plates the coefficient ml shall be taken as per Table. Coefficient value ml in case of fastening the cables in end anchorages shall be taken:

ml = 0.95, when casting the cable end in conic or cylindrical cavity of the body with alloyed non-ferrous metal at a length not less than 5 diameters of cable;

ml = 1, when casting the cable end in conic cavity of the body with epoxy compound at a length not less than 4 cable diameters.

ml = 1, in case of wedge anchor, use of aluminium shims and filling the voids with epoxy compound; ml = 1 in anchor with flattering the ends of round wires, fixing them in anchor plate and filling the voids with epoxy compound with

filler of steel shot. q, MN/m (tf/cm) 1(1) 2(2) 4.9(5) 9.8(10

) 14.7(1

5) 19.6(2

0)

Coefficient ml 1 0.99 0.98 0.96 0.93 0.85

APPENDIX 15 ,

Compulsory

COEFFICIENTS FOE STABILITY DESIGN OF BARS AND BEAMS Table 1*

Coefficients ϕ, ϕ c, ϕ b for stability design of bars and beams of steel 16 Д by GOST 67)3—91 and СтЗ by GOST 14637—89 and GOST 535—88

Flexibilityλ, λv,

0 0.10 0.25 0,50 0.75 1,00 1.50 2.00 2,50 3,00 3,50 4,00 5,00 0

0,93 0,85 0,79 0,68 0,60(0,58) 0,52(0,50) 0,43(0,41) 0,35 0,30 0,27 0,24 0,21 0,17 10 0,92 0,84 0,78 0,68(0,67) 0,60(0,57) 0.52(0,50) 0,42(0.40) 0,35 0,30 0,26 0,23 •0,21 0,17 20 0,90 0,83 0.77(0,76) 0,67(0,66) 0,58(0,56) 0,50(0,49) 0,41(0,40) 0,34 0,29 0,26 0,23 0,21 0,17 30 0,88 0,81 0,76(0,73) 0,65(0,63) 0,56(0,54) 0,49(0,47) 0,40(0,39) 0,33 0,29 0.25 0,22 0,21 0.17 40 0,85 0,79(0,77) 0,73(0,70) 0,63(0,61) 0,54(0,52) 0,47(0,45) 0.39(0,38) 0,32 0.28 0,24 0.22 0,20 0,17 50 0,82(0,8

0) 0,76(0,73) 0,70(0,65) 0.60(0,57) 0,51(0,49) 0.45(0,43) 0,37(0,36) 0.31 0,27 0,24 0.22 0,20 0,16

60 0,78(0,73)

0,72(0,66) 0,66(0.60) 0,57(0,53) 0,49(0.46) 0.43(0,41) 0,35(0,34) 0.30 0,26 0,23 0.21 0,19 0,16

70 80 0.74(0,66) 0,69(0,6

0,67(0,60) 0,62(0.54)

0,62(0,54) 0,57(0.49)

0,54(0,48) 0,50(0.43)

0.46(0,42) 0.43(0,39)

0,41(0,38) 0,38(0,36)

0,34(0,32) 0,32(0,31)

0,29 0,28 0,25 0.24

0,22 0,22

0,20 Q20

0.19 0.19

0,16 0,15

,50;52

5010;157.0

3

33

>>

≤≤+≥

s

s

ddD

dddD

SNiP 2.05.03-84 Page 179 90 0,63(0.5

4) 0.56(0,49) 0,51(0,44) 0,45(0,40) 0.40(0,36) 0,36(0,33) 0,30(0,28) 0,26 0,23 0,21 0.19 0,18 0,15

100 0,56(0,49)

0,49(0,44) 0.45(0,40) 0,41(0,37) 0,37(0,33) 0,33(0,30) 0,29(0,26) 0,25 0,22 0,20 0,19 - 0.17 0,14

110 0.49(0.44)

0,43(0,40) 0,41(0,37) 0,37(0,34) 0,34(0,31) 0,31(0,29) 0,27(0,25) 0,24 0,21 0,19 0,18 0,17 0,14

120 0,43(0.41)

0,39(0,37) 0,37(0.34) 0.34(0,31) 0.31(0,28) 0,29(0,27) 0,25(0,23) 0,22 0,20 0,18 0,17 0.16 0,13

130 0,38(0,37)

0,35(0,34) 0.33(0,31) 0,31(0,29) 0,29(0,27) 0,26(0,25) 0,23(0,22) 0,21 0.19 0,17 0,16 0,15 0,13

140 0,34 0,31 0,30(0,29) 0,28(0,27) 0,26(0,25) 0,24(0.23) 0,21 0.20 0,18 0,16 0,15 0,14 0.12 150 0.31 0,28 0,27 0,25 0,23 0,22 0,20 0,18 0.16 0,15 0,14 0.14 0,12 160 0,28 0,26 0,24 0,23 0,22 0,21 0.19 0,17 0.15 0,14 0,14 0,13 0,11 170 0,25 0.24 0,22 0,21 0,20 0,19 0.17 0.16 0,15 0,14 0,13 0,12 0,11 180 0,23 0,21 0,20 0.19 0,19 0,18 0,16 0,15 0.14 0,13 0,12 0.11 0,10 190 0,21 0,20 0,19 • 0,18 0.17 0,17 0,15 0,14 0.13 0,12 0,12 0,11 0,10 200 0,19 0,19 0.18 0.18 0,17 0,16 0.15 0,14 0.13 0,12 0,11 0,11 0.10

Notes. For rolled I-beams with parallel faces of flanges and melded members of I-beam and H-shapedthe coefficients ϕ, ϕ c, ϕ b as per present Appendix are used at own residual compressive stresses on flange edges not more than 49 MPa (500 kgf/cm2). For members of mentioned type with own residual compressive stresses on flange edges above 49 Mpa (500 kgf/cm2) when stability is designed in plane of flanges the used coefficients ϕ, ϕ c, ϕ b are given in brackets.

Table 2 Coefficients ϕ, ϕ c, ϕ b for stability design of bars and beams of steel 15ХСНД by GOST 6713-91 and 345-10Г2С1Д. 345-10Г2С1. 325-09Г2СД, 325-09Г2С, 295-09Г2Д, 295-09Г2 and 325-14Г2 by GOST 19281—fl9' at reduced relative eccentricity

Flexibility λ, λv, λy, λcf

0 0.10 0.25 0.50 0,75 1,00 1,50 2.00 2.50 3,00 3.50 4.00 5,00

0 0.93 0,86 0,78 0,69 0,62 0,54 0,44 0,34 0,28 0,24 0.22 0,20 0,17

10 0.92 0,84 0,77 0,68 0,60 0,52 0,43 0,34 0.28 0,24 0.22 0,20 0,17

20 0,90 0,83 0.76 0,66 0,58 0,51 0,41 0.33 0,28 0,24 0,22 0,20 0,17

30 0,88 0.81 0,73 0,63 0,56(0,55) 0,49(0,48) 0,40(0,39) 0,32 0,27 0,24 0.21 0.19 0,16

40 0.85(0.84)

0,77(0,76)

0.69(0,68)

0,59(0,5Ц) 0.52(0,51) 0,46(0,45) 0,38(0,37) 0.31 0,26 0,23 0,21 0.19 0,16

50 0,80(0,78)

0,72(0.70)

0,64(0,62)

0,54(0,52) 0,48(0,46) 0.43(0,42) 0.36(0,35) 0.30 0,25 0,22 0,21 0.19 0,16

60 0,74(0,71)

0,66(0,63)

0,58(0,56)

0,48(0,46) 0,43(0,41) 0,39(0,38) 0,33(0,32) 0.28 0,25 0,22 0,20 0.-18 0,15

70 0.67(0,63)

0,58(0.55)

0,51(0,49)

0,43(0,41) 0,39(0.37) 0,35(0,34) 0,30(0.29) 0,27 0,23 0,21 0,20 0.18 0,15

80 0,58(0,53)

0,50(0,46)

0,45(0,42)

0,38(0.35) 0,35(0,33) 0.32(0,31) 0.27(0,26) 0,25 0.22 0,20 0,18 0.17 0,14

90 0,48(0,43)

0,43(0,39)

0,40(0,37)

0,34(0,31) 0,31(0,29) 0,29(0,28) 0,25(0.24) 0,23 0,21 0,19 0,18 0,16 0,14

100 0,40(0,36)

0,38(0,34)

0,35(0,32)

0,30(0,27) 0,26(0,26) 0,26(0,25) , 0.23(0,22) 0.21 0,19 0,18 0.17 0,16 0,13

110 0,35(0,32)

0,33(0,30)

0.31(0,29)

0,27(0,25) 0,25(0,24) 0,23(0,22) 0,21(0,20) 0,20 0,19 0,17 0,16 0,15 0,13

120 0,30(0,28)

0,29(0.27)

0,27(0.26)

0,24(0,23) 0.23(0,22) 0,22(0,21) 0.19(0,18) 0,18 0,17 0,16 0,15 0,14 0,12

130 0,27(0.25)

0,25(0.24)

0,24(0.23)

0,22(0,21) 0.21(0,20) 0.19(0,18) 0,18(0,17) 0.17 0,16 0,15 0,14 0,13 0,12

140 0,24(0,23)

0,23(0,22)

0.22(0.21)

0.20(0.19) 0.19(0,18) Q.18'0,17) 0,17(0.16) 0,16 0,15 0,14 0,13 0,13 0.11

150 0.22 0.21 0,20 0.18 0,17 0,17 0,15 0.14 0,13 0,13 0,12 0.11 0,10

160 0,20 0.19 0,18 0,17 0,16 0.15 0.14 0,14 0,13 0,12 0,12 0.11 0,10

170 0.18 0.17 0,16 0,15 0,14 0,14 0,13 0,12 0,12 0.11 0.11 0,10 0,09

180 0.16 0.16 0.15 0,14 0,13 0.13 0,12 0,12 0,11 0,11 0,10 0.10 0,09

SNiP 2.05.03-84 Page 180 100 0,15 0.14 0.13 0.13 0,12 0,12 0,11 0,10 0,10 0.10 0,09 0,09 0,08

200 0.13 0.13 0.12 0.12 0,11 0,10 0,10 0.09 0,09 0.09 0,08 0.08 0,08

Note. Refer to Note of Table 1*'. Тable 3

Coefficients ϕ, ϕ c, ϕ b for stability design of bars and beams of steel ЮХСНД by GOST 6713—91 and 390-14Г2АФД, 39в-15Г2АФДпс by GOST 19281—69" at reduced relative eccentricity

Flexibility

λ, λv,

λy, λcf

0 0,10 0.25 0,50 0,75 1,00 1,50 2,00 2.50 3,00 3,50

4,00

5,00

0 0,93 0,86 0,78 0,70 0,63 0.55 0.45 0.35 0,29 0,25 0,23

0,21

0,18

10 0,92 0,84 0.77 0,68 0,60 0,52 0,43 0.34 0,28 0.24 0.22

0,20

0.1.7

20 0,90 0.83 0,76 0,66 0,58 0,51 0,41 0.33 0,28 024 0,22

0,20

0.17

30 0,88 0,81 0,73 0,63 0,55 0,48 0,39 0,32 0.27 0.24 0.21

0.19

0,16

40 0,84(0.83) 0,76(0,75) 0,68(0.67) 0,58(0,57) 0,51(0,50) 0,45(0.44) 0,37(0,36) 0,31(0.30) 0,26(0,25) 0,23(0,22) 0,21(0,20)

0,19(0.18)

0,16(0.15)

50 0,79(0.77) 0,71(0,69) 0,63(0,61) 0.53(0,51) 0,47(0,45) 0,43(0,41) 0,36(0.34) 0,31(0.29) 0,26(0,24) 0,23(0,21) 0,21(0,20)

0,19(0,18)

0,16(0,15)

60 0.73(0.70) 0,65(0,62) 0,58(0,55) 0,48(0.45) 0,43(0,40) 0,40(0,37) 0,34(0,31) 0,30(0,27) 0.26(0.24) 0,23(0,21) 0.21(0,19)

0,19(0,17)

0,16(0,14)

70 0,63(0.59) 0,55(0,51) 0,49(0,45) 0,41(0,37) 0,39(0,33) 0,36(0,30) 0,31(0,25) 0.29(0,23) 0,25(0.19) 0,23(0,17) 0,21(0,16)

0,19(0,14)

0,16(0,11)

80 0,53(0,49) 0,46(0,42) 0,42(0,38) 0,35(0,31) 0,33(0.29) 0,31(0,27) 0,26(0,22) 0,25(0,21) 0,22(0,18) 0,20(0,16) 0.18(0,14)

0,17(0,13)

0,14(0,10)

90 0,43(0,38) 0,39(0,34) 0,37(0,32) 0,31(0,26) 0.29(0,24) 0,28(0,23) 0,24(0,19) 0,23(0.18) 0,21(0,16) 0,19(0,14) 0,18(0,13)

0,17(0,11)

0,14(0,09)

100 0,35(0,32) 0.33(0,30) 0.31(0,28) 0,26(0,23) 0,25(0,22) 0,24(0,21) 0,21(0,18) 0,20(0,17) 0.19(0,15) 0,19(0,14) 0,18(0,13)

0,17(0,11)

0,14(0,08)

110 0.30(0,27) 0,28(0,25) 0,27(0,24) 0,23(0.20) 0,22(0,19) 0,20(0,17) 0.18(0,15) 0,18(0,15) 0,17(0,14) 0,15(0,12) 0,15(0,11)

0.15(0.10)

0,13(0,08)

120 0,26(0,24) 0,25(0,23) 0,24(0,22) 0,21(0,19) 0.20(0,18) 0.19(0,17) 0.16(0,14) 0,16(0,14) 0,15(0,13) 0,14(0.12) 0,13(0,11)

0,12(0.10)

0,10(0.08)

130 0.23(0,21) 0,22(0,20) 0,21(0,19) 0,19(0,17) 0,18(0,16) 0,17(0,15) 0,15(0,13) 0,15(0,13) 0.14(0,12) 0,13(0,11) 0.12(0,10)

0,11(0.09)

0.10(0,08)

140 0,21(0,20) 0,20(0,19) 0,19(0,18) 0,17(0,16) 0.16(0,15) 0,16(0,15) 0,14(0,13) 0,14(0.13) 0,13(0,12) 0,12(0.11) 0,11(0,10)

0.11(0,09)

0,09(0,08)

150 0,19 0,18 0,17 0,15 0,14 0,14 0.12 0,11 0,10 0,10 0,09

0,08

0,07

160 0,17 0,16 0.15 0,14 0.13 0,12 0,11 0,11 0,10 0.09 0,09

0,08

0,07

170 0,15 0.14 0,13 0,12 0,11 0.11 0,10 0,09 0,09 0.08 0,08

0,07

0,06

180 0,13 0.13 0,12 0,11 0.10 0.10 0.09 0,09 0,08 0,08 0,07

0,07.

0,06

190 0.12 0,11 0,10 0,10 0.09 0.09 0.08 0,07 0,07 0.07 0,06 ,

0,06

0,05

200 0.11 0,11 0.10 0.10 0,09 0.08 0.07 0.06 0,06 0,06 0,05

0,05

0,05

Note. Refer to Note of Table 1*. Coefficient of section shape influence, η

Coefficients of section shape influence η , when determined the reduced relative eccentricity by Formula e tf = e tref should be taken according to Appendix 6 of SNiP II-23-81* calculating, at this, the conventional flexibility by Formula

Where αR – coefficient taken as per Table 4 , at this m = e ref. Table 4

Steel quality Thickness of rolled stock, mm Coefficient αR value

16Д Up to 20 0.0324 21-40 0ю0316 41-60 0.0309

Rλαλ =

SNiP 2.05.03-84 Page 181 15ХСНД 8-32 0.0378 33-50 0.0372 10ХСНД 8-40 0.0412 390-14Г2АФД 4-50 0.0415 390-15Г2АФДпс 4-32 0.0415

APPENDIX 16*

Compulsory

STABILITY DESIGN OF FLANGES AND WEBS OF MEMBERS SUPPORTED BY STIFFENERS

1. Rectangular sections of flanges and webs (further referred as plates) put in between orthogonal members supporting them by contour (stiffeners, flange for web and web for flanges) shall be designed for stability. In so doing, the following designed

dimensions and parameters of the plate to be checked are considered: a – the plate length equal to distance in between axes of cross stiffeners;

hef – designed width of the plate equal to: the distance in between the axes of flanges hw or axes of boxed web b∫, if rolled or bolted member has no stiffeners;

the distance in between the nearest marks of flange angles, if a composite member with bolt connections has no stiffeners; the distance from the flange (web) axis to the axis of the end longitudinal stiffeners h1 and hn, or to the distance in between axes of

adjacent longitudinal stiffeners hi (i = 2; 3; 4; 5…), if bolted or rolled member has longitudinal stiffeners; the distance from the end stiffener axis to the nearest mark of flange angle h1 and hn, or to the distance in between axes of adjacent

longitudinal stiffeners hi (i = 2; 3; 4; 5…), if a composite member with bolt connection has longitudinal stiffeners; t – the thickness of the plate to be checked;

t1, b1 – the thickness and designed width of the sheet orthogonal to the plate under check; into design width of the this sheet the following shall be included (to each side from the plate under check): in I-section - a part of the sheet ξ1 t1 wide, but not more than the width of overhang, but in box-section – a part 1/2 ξ2 t1, but not more than a half of the distance between box webs (here coefficients ξ1

and ξ2 shall be determined as per the item 4.55*); here σ and ‾σ are determined as per the item 2;

μ = a/hef;

here β is a coefficient taken as per Table1. Table 1

Type of compressed chord fixing by the roadway structure Value of coefficient β Bridge beams are fixed to the chord by hook bolts 0.3

Precast reinforced concrete roadway slabs are fixed to the chord by high-tension pins and timber pads

0.5

Chord is free 0.8

Sheets of orthotropic plate is welded to the chord by lap joints and butt joints

2.0

Precast roadway of composite span is fixed to the chord by embedded metals and high-tension bolts

1.5

Composite span roadway is fixed to the chord continuously along the total span length by high-tension bolts and grouting by cement sand

mortar

20

SNiP 2.05.03-84 Page 182 If the plate under check is jointed to the faggot consisted of 2 and more sheets, the thickness and design width of the first faggot sheet

which directly joins to the given plate is taken to t1 and b1. 2. Design on plates stability shall be made with regard for all components of stressed state – σx, σy, τxy.

Stresses σx, σy, τxy shall be calculated in assumption of elastic behavior of materials by the gross section without regard for coefficients of longitudinal bending.

Maximum σx and minimum ‾σx longitudinal normal stress (positive under compression) by the plate longitudinal borders shall be calculated by formulae

where

ymax, ymin – maximum and minimum distance from the neutral axis to the plate longitudinal border (with regard for the sign); Mm – average value of bending moment within the section if μ ≤ 1; if the length of the section is more than its design width, then Mm shall be calculated for more stressed part with the length equal to the width of the section; if the moment changes the sign within the

section, then Mm shall be calculated on the part of section with the moment of one sign. Average tangential stress τx shall be defined: when longitudinal stiffeners are not available – by formula

where

when longitudinal stiffeners are available – by formula

In formulae (3) and (4): Qm – average value of transverse force within the section calculated like Mm;

τ1, τ2 – values of tangential stresses on plate longitudinal borders calculated by formula (3) when Smax is substituted by relative values S.

Transverse normal stress σy (positive under compression) acting on the outer edge of the end plate shall be defined: due to movable load – by formula

where

P – distributed pressure on the outer edge of the end plate, defined in accordance with the Compulsory Appendix 5*; due to concentrated pressure of force F – by formula

where lef – conventional length of load distribution.

Conventional length of load distribution lef shall be defined:

when load is transferred directly through the beam chord or through the rail and chord – by formula where

SNiP 2.05.03-84 Page 183

c – coefficient equal to 3.25 for welded and rolled members, to 3.75 for members with high-tension bolts connections, to 4.5 for members with common bolts connections.

I – inertia moment of beam chord or sum of inertia moments of chord and rail; when load is transferred from the roller through the rail, timber solepiece and beam chord lef shall be taken as equal to 2h

(where h is the distance from the rail surface to the plate edge), but not more than the distance in between the neighboring rollers.

Transverse normal stresses σy on the border of the second and subsequent plates shall be defined, as a rule, by the theory of elasticity.

They are allowed to be defined: under the load distributed along the total length of the plate – by formula

under the concentrated load – by formula

In formulae (8) and (9):

where h0 – a part of web height equal to the distance from the axis of loaded chord in welded and rolled beams, or from the nearest mark of

flange angle of beams with bolt connections to the border of the plate under check; hw – the total web height.

3. Critical stresses σx,cr, σy,cr, τxy,cr, σx,cr,ef, σy,cr,ef, τxy,cr,ef shall be defined in assumption of only one from studied stresses σx, σy, and τxy. In general cases the reduced critical stresses σx,cr,ef, σy,cr,ef, τxy,cr,ef are calculated in the assumption of material unlimited

elasticity on the basis of stability theory of the first kind (bifurcation of equilibrium forms) for Values of parameters shown in Tables 2, 4-13 for determination of critical stresses in plates can be defined by linear

interpolation. 4. Stability design for the web of solid bent members, which have transverse stiffeners only, shall be calculated by formula

where σx,cr, σy,cr – critical normal stresses, longitudinal and transverse ones accordingly;

τxy,cr – critical tangential stress; ω1 – coefficient taken as per Table 2.

coefficient introduced when highway and city bridges are under design and hw/t > 100. Table 2

ξ 0 0.5 1.0 1.5 2.0 3.0 4.0 ω1 1.00 1.05 1.10 1.15 1.20 1.30 1.40

Critical stresses σx,cr, σy,cr, τxy,cr shall be calculated by formula of Table 3 depending on the reduced critical stresses σx,cr,ef,σy,cr,ef,τxy,cr,ef, calculated as per items of 4.1-4.3 of this Appendix. In so doing, τxy,cr shall be calculated by formulae for σx,cr substituting the

following relations into them: Table 3*

SNiP 2.05.03-84 Page 184

Steel Quality 16Cu

Values Range σx,cr,ef MPa (kgf/cm2) 0-196

(0-2000)

96-385 (2000-3921)

More than 385 (more than 3921)

Steel Quality 15CrSiNiCu

Values Range σx,cr,ef MPa (kgf/cm2)

0-207 (0-2111)

207-524 (2111-5342)

more than 524 (more than 5342)

Steel Quality 10CrSiNiCu

390-14Mn2NVCu 390-14Mn2NVCu sk

Values Range σx,cr,ef MPa (kgf/cm2) 0-229

(0-2333)

229-591 (2333-6024)

SNiP 2.05.03-84 Page 185

more than 591 (more than 6024)

* When calculating transverse normal critical stresses in formulae σx,cr, is replaced by σy,cr and σx,cr,ef is replaced by σy,cr,ef . Here m – working mode coefficient, taken as per Table 60*.

4.1. Reduced critical longitudinal normal stress for flexural member web plates shall be calculated by formula

where χ - coefficient of web elastic restraint equal to 1.4 for members with bolt connections, and taken as per Table 4 for welded members;

ε - coefficient taken as per Table 5. Table 4

γ 0.25 0.5 1.0 2.0 4.0 10.0 More than 10 χ 1.21 1.33 1.46 1.55 1.60 1.63 1.65

Table 5

ξ Values of coefficient ε, if µ is equal to 0.4 0.5 0.6 0.67 0.75 0.8 0.9 1.0 1.5 2 and

more 0 8.41 6.25 5.14 4.75 4.36 4.2 4.04 4.0 4.34 4.0

0.67 10.8 8.0 7.1 6.6 6.1 6.0 5.9 5.8 6.1 5.8 0.80 13.3 9.6 8.3 7.7 7.1 6.9 6.7 6.6 7.1 6.6 1.00 15.1 11.0 9.7 9.0 8.4 8.1 7.9 7.8 8.4 7.8 1.33 18.7 14.2 12.9 12.0 11.0 11.2 11.1 11.0 11.5 11.0 2.00 29.1 25.6 24.1 23.9 24.1 24.4 25.6 25.6 24.1 23.9 3.00 54.3 54.5 58.0 53.8 53.8 53.8 53.8 53.8 53.8 53.8 4.00 95.7 95.7 95.7 95.7 95.7 95.7 95.7 95.7 95.7 95.7

Table 6 μ Values of coefficient ζ, if ρ is equal to 0.10 0.11 0.12 0.13 0.14 0.15 0.16 0.18 0.20 0.25 0.30 0.35

0.5 1.70 1.67 1.65 1.63 1.61 1.60 1.60 1.60 1.60 1.60 1.60 1.60 0.6 1.98 1.93 1.89 1.85 1.82 1.80 1.79 1.78 1.76 1.72 1.71 1.69 0.7 2.23 2.17 2.11 2.06 2.02 1.98 1.96 1.93 1.89 1.82 1.79 1.76 0.8 2.43 2.35 2.28 2.22 2.17 2.12 2.10 2.05 2.01 1.91 1.86 1.82 0.9 2.61 2.51 2.43 2.36 2.30 2.24 2.21 2.16 2.11 1.98 1.92 1.87 1.0 2.74 2.64 2.55 2.47 2.40 2.34 2.31 2.24 2.17 2.04 1.97 1.91 1.2 2.79 2.68 2.59 2.51 2.43 2.37 2.33 2.26 2.19 2.05 1.98 1.91 1.4 2.84 2.73 2.63 2.54 2.46 2.39 2.35 2.28 2.21 2.05 1.98 1.91 1.5 2.86 2.75 2.65 2.56 2.48 2.41 2.37 2.30 2.22 2.07 1.99 1.91 2.0 and

2.86 2.75 2.65 2.55 2.47 2.40 2.36 2.28 2.20 2.05 1.96 1.88

SNiP 2.05.03-84 Page 186

more In Table 6 the following is designated: ρ = 1.04 lef/hef

4.2. Reduced critical transverse normal stress σy,cr,ef for plates of flexural member web shall be calculated by formula where

∂ - coefficient equal to 1 under the load distributed along the total length of the plate, and taken as per Table 6 – under the concentrated load;

χ – coefficient of elastic restraint taken as per Table 7; z – coefficient taken as per Table 8.

Table 7 Γ Values of coefficient χ if μ is equal to 0.4 0.6 0.8 1.0 1.5 2.0 and more

0.25 1.19 1.19 1.20 1.20 1.19 1.18 0.5 1.24 1.29 1.30 1.32 1.32 1.32 1.0 1.28 1.36 1.41 1.47 1.52 1.56 4.0 1.32 1.45 1.57 1.73 1.97 2.21

10 and more 1.34 1.49 1.65 1.88 2.51 2.95 Table 8

μ Z μ z

0.4 4.88 1.2 6.87 0.5 5.12 1.4 7.69 0.6 5.37 1.6 8.69 0.7 5.59 1.8 9.86 0.8 5.80 2.0 11.21 1.0 6.26 2.5 and more 15.28

4.3. Reduced critical tangential stress τxy,cr,ef for flexural members web plates shall be calculated by formula where

d – the smallest side of section (a or hef); μ1 – coefficient equal to μ, if a > hef, and 1/μ, if a < hef;

χ – coefficient of elastic restraint equal to 1 for members with bolt connections and taken as per Table 9 for weld connections. Table 9

γ Values of coefficient χ if μ is equal to 0.5 0.67 1.0 2.0 2.5 and more

0.25 1.014 1.063 1.166 1.170 1.192 0.5 1.016 1.075 1.214 1.260 1.300 1.0 1.017 1.081 1.252 1.358 1.416 2.0 1.018 1.085 1.275 1.481 1.516 5.0 1.018 1.088 1.292 1.496 1.602

10.0 1.018 1.088 1.298 1.524 1.636 More than

10.0 1.018 1.089 1.303 1.552 1.680

SNiP 2.05.03-84 Page 187

5. Design for stability of solid flexural members web plates, which have transverse ribs and one longitudinal rib in compressed zone, shall be calculated:

for the first plate – in between compressed chord and longitudinal rib, by formula where

ω1 – coefficient, taken as per Table 2; σx, σy, τxy – stresses determined as per item 2;

σx,cr, σy,cr, τxy,cr – critical stresses determined as per item 4; for the second plate – in between tensioned chord and longitudinal rib, by formula (10), taking ω2 = 1.

5.1. Reduced critical longitudinal normal stress σx,cr,ef shall be calculated by formula (11); in so doing, elastic restraint coefficient χ shall be taken:

for the first plate - χ = 1.3 – for members with bolt connections; χ = 1.35 –for members with bolt connections and welded members when integrated with composite slab; as per Table 10 – for other weld members;

for the second plate - χ = 1.

Table 10 γ 0.5 1.0 2.0 5.0 10 and more χ 1.16 1.22 1.27 1.31 1.35

5.2. Reduced critical transverse normal stress σy,cr,ef in the first plate shall be calculated by formula

where i – coefficient equal to 1.0, if µ = a/h1 ≥ 0.7 and to 2.0, if 0.7 > µ > 0.4;

χ - coefficient of elastic restraint taken as per Table 11 for members integrated with composite slab, and for beams with bolt connections, and as per Table 12 – for welded beams.

Table 11 µ 0.5 0.8 1.0 1.5 2.0 and more χ 1.07 1.18 1.31 1.52 1.62

Table 12 γ Values of coefficient χ if μ is equal to 0.5 0.6 0.9 1.0 1.5 2.0 2.5 3.0 2 1.06 1.07 1.13 1.17 1.31 1.32 1.29 1.25 4 1.06 1.07 1.14 1.19 1.38 1.44 1.43 1.39

Reduced critical transverse normal stress σy,cr,ef being under the action of concentrated load, when acting stresses are calculated by formula (6), shall be calculated by formula (15) multiplying to coefficient 1,55; if in this case a > 2h1 + 2lef, then μ shall

be equal to: Reduced critical transverse normal stress σy,cr,ef in the second plate shall be calculated by formula (12); in so doing, the

following shall be taken: χ = 1; z – as per Table 8; ∂ - as per Table 6, if ρ = 0.35. 5.3. Reduced critical tangential stress τy,cr,ef shall be calculated by formula (13), but the coefficient χ1 = 1+ χ/2 should be

taken instead of restraint coefficient χ for the first plate and χ = 1 for the second plate.

SNiP 2.05.03-84 Page 188

6. Design for stability of solid flexural members web plates, which have transverse ribs and some longitudinal stiffeners, shall be done:

for the first plates – in between compressed chord and the nearest rib, by formula (14) and formulae (11), (15) and (13) for σx,cr,ef,σy,cr,ef,τxy,cr,ef accordingly;

for subsequent compressed plates – by the same formulae as for the first plate, taking restraint coefficient χ = 1; for compressed-tensioned plate – by formula (10), taking ω1 = 1, and formulae (11), (15) and (13) for σx,cr,ef,σy,cr,ef,τxy,cr,ef

like for the second plate as per item 5. Design for stability of web tensioned zone plate shall be calculated by formula

where σx,cr,σxy,cr - critical transverse normal and tangential stresses, defined as per σy,cr,ef, and τxy,cr,ef according to requirements of item 4; in

so doing, reduced critical transverse normal stress σy,cr,ef shall be calculated by formula

where δ - coefficient taken as per Table 13.

Reduced critical tangential stress τxy,cr,ef shall be determined: for plate, adjoining to the tensioned chord, by formula

for intermediate tensioned plate - by formula

where d – the smallest side of the section (a or hef);

μ1 – coefficient equal to μ, if a > hef, and 1/μ, if a < hef; Table 13

Type of plate Values of coefficient δ, if a/hef 0.4 0.5 0.6 0.7 0.8 1.0 1.5 2.0

Plate adjoining to the compressed chord

1240 1380 1520 1650 1820 2240 3860 6300

Intermediate plate 920 970 1020 1060 1100 1190 1530 2130 Note: a and hef shall be defined as per item 1.

7. Design for stability of solid compressed-flexural members web plates (stiffening girder of strut system span structure, arch or tower) under compression of section along the total height, shall be calculated by formula

where

σx – maximum longitudinal normal stress at the plate edge caused by longitudinal force N and bending moment Mm that is taken as per item 2;

ω1 – coefficient defined as per Table 2; σy, τxy – transverse normal and average tangential stresses, defined as per item 2;

)20(,1)(1.11.1 2

,,,1

≤++crxy

xy

cry

y

crx

x

τ

τ

σ

σ

σωσ

SNiP 2.05.03-84 Page 189

σx,cr, σy,cr, τxy,cr – critical stresses defined as per σx,cr,ef,σy,cr,ef and τxy,cr,ef according to requirements of item 4. Design shall be made as for the web of solid flexural member (see items 4-6), when tensioned stresses are acted on the

parts of section height.

APPENDIX 17*

Compulsory

COEFFICIENTS FOR ENDURANCE DESIGN Table 1

Efficient Factor of Stresses β Concentration for Endurance Design of Bridge Steelworks

Location of design section and structure characteristics Factor β for steel qualities 16Cu 15CrSiNi Cu,

10CrSiNi Cu, 390-14Mn2NVCu,

390-15Mn2NVCu,sk 1. By the main metal after abrasive cleaning or with untreated

rolled surface of details with rolled or treated by milling or gouging edges in sections out of welds and bolts

1.0 1.0

2. Ditto with edges treated by gas machine cutting: a) of normal quality 1.1 1.2

b) final cutting (washout, cutting with oxygen curtain, oxygen and plazma cutting)

1.0 1.0

3. By the main metal of details in: a) net section by connection bolts of composite members, and at the

free hole as well (see dwg.1) 1.3 1.5

b) net section at the hole with installed high-tension bolt tightened for the characteristic force (see dwg.2)

1.1 1.3

c) gross section by the first row of high-tension bolts in fastening of joint plate to solid beam chords, which are not butt-jointed in the

given node, and to lattice truss members (see dwg.3)

1.3mf 1.5mf

d) Ditto, in fastening to the node or in butt-joint of double-web members with:

directly overlapped part of section (2Av) consists of not less than, %: 80 of the total section area, including the case when double straps

are used – 60 (dwg.4)

1.4 mf 1.6 mf

directly overlapped part of section (2Av) consists of not less than, %: 60 of the total section area, including the case when double straps

are used – 40 (dwg.4)

1.5 mf 1.7 mf

e) Ditto, in fastening or in butt-joint with single straps of double-web members with directly overlapped part of section (2Av) consists

of from the total section area, %:

60 and more 1.6 mf 1.8 mf less than 60 1.7 mf 1.9 mf

f) Ditto, in fastening to the node or in butt-joint with single straps of monoweb members (dwg.6)

2.2 mf 2.5 mf

4. By the main metal of details in the section by the border of unfinished butt joint with reinforcement, having smooth transition

(if sheets of the same thickness and width are butt jointed)

1.5 1.8

SNiP 2.05.03-84 Page 190

5. By the main metal of details in the section by the zone of transition to the butt joint, finished in this part by abrasive disk or

milling cutter when butt jointing sheets:

a) of the same thickness and width 1.0 1.0 b) of different width in the section by the narrowest sheets 1.2 1.4 c) of different thickness in the section by the thinnest sheet 1.3 1.5

d) of different thickness and width in the section by the sheet with the less area

1.6 1.9

6. By the main metal of lap connected member in the section by the border of transverse fillet:

a) without mechanical treatment of this joint if the relation of its legs is b:a ≥ 2 (when the bigger leg b is directed along the force)

2.3 3.2

b) Ditto, if legs relation is b:a = 1.5 2.7 3.7 c) when this joint is mechanically treated and legs relation is b:a ≥ 2 1.2 1.4

d) Ditto, if legs relation is b:a = 1.5 1.6 1.9 7. By the main metal of the member overlap connected by longitudinal fillets, in the section by the ends of these fillets

independently on their treatment

3.4 4.4

8. By the main metal of tensioned beam chords and trusses members in the section by the border of transverse fillet, which

connect diaphragms or stiffening rib:

a) without mechanical treatment of the joint, but under the presence of smooth transition from the joint to the main metal when:

manual welding is used 1.6 1.8 semi-automatic submerged arc welding is used 1.3 1.5

b) when joint is mechanically treated by milling cutter 1.0 1.1 9. Sections of composite members from sheets connected with

continuous transverse joints automatically welded under the force action along joint axis

1.0 1.0

10. By the main members metal in places where the following members are broken:

a) joint plates butt welded to the chord edges of beams and trusses or tee-welded to beams web or chords, and also to truss members, in

case of smooth curve form and mechanical treatment of transition from joint plate to the chord, in case of full penetration of joint plate

thickness

1.2 1.4

b) both chords on the I-section web under the condition of gradual reduction of width and thickness of chord to the place of breaking,

connection of web to the chords at the end area with full penetration and mechanical treatment of chord transition to the web

1.3 1.6

c) one sheet of faggot of welded beam chord when the thickness is reduced to the place of breaking with the slope to steeper the 1:8,

and the sheet thickness, reducing the thickness to the zero, with the slope not steeper than 1:4 and with mechanical treatment of welds

ends

1.2

1.4

d) cover plate for strengthening of member section, weakened by holes (compensator of weakening) in case of symmetrical decrease of its width with reducing to zero, with slope not steeper 1:1 and

with mechanical treatment of joint ends

1.2 1.4

11. By the main metal of roadway members in sections by the end row of high-tension bolts in fastening of:

a) diagonals of longitudinal bracings to the lower chord of 1.1 1.3

SNiP 2.05.03-84 Page 191 longitudinal beam, and also temporary bracings to the lower chord

of cross beam b) joint plates of horizontal diaphragm to the lower chord of bridge

deck stringer 1.3 1.5

c) temporary bracings to the upper chord of transverse beam 1.6 1.8 12. By the axis of butt joint with full penetration of joint root:

a) when using submerged arc automatic or semiautomatic welding with control by ultrasonic testing

1.0 1.0

b) Ditto, without ultrasonic inspection 1.2 1.4 13. By reference section of fillet weld:

a) transverse fillet, welded by: manual welding 2.3 3.2

submerged arc automatic and semiautomatic welding 1.9 2.4 b) longitudinal fillet 3.4 4.4

c) longitudinal connecting joint of composite member at the area of its fastening to the node

if only a part of section is directly lapped by cover plates or hitch

plates 1.5 1.7

d) longitudinal sircumferential joint of a beam 1.7 1.9 14. By the main metal of orthotropic deck plate in the zone of

transition to erection butt joint, made by single-side submerged arc automatic welding:

a) with application of the first layer by manual welding with flux copper backing plate, without mechanical treatment of

strengthening

2.4 2.7

b) ditto, with mechanical treatment of strengthening from the opposite side of butt joint

1.6 1.8

c) on the glass cloth and copper back-up plate using granulated metal chemical additive, without mechanical treatment of

strengthening

1.5 1.65

15. By the main metal of the orthotropic plate deck in the zone of transition to the overhead fillet weld of its field lap connection with

the chord of the main beam or truss:

a) made by manual welding 6.4 7.1 b) ditto, using erection strip insert butt welded to orthotropic plate

edges lap fixed to the chord of the beam 3.8 4.2

16. By the main metal of steel plates of orthotropic deck in the zone of transition to its field butt joint with the chord of main beam or

truss made by single-side submerged arc automatic welding:

a) with application of the first layer by manual welding with flux copper backing plate with mechanical treatment of strengthening

from the reverse side of butt joint if the thickness of plates to be butt jointed is equal

1.6 1.8

b) ditto, if the thickness of sheets to be butt jointed is different 1.8 2.0 c) on the glass cloth and copper back-up plate using granulated

metal chemical additive, without mechanical treatment of strengthening if the thickness of plates to be butt jointed is equal

1.5 1.65

d) ditto, if the thickness of sheets to be butt jointed is different 1.7 1.9 17. By the main metal of in the zone of crossing of longitudinal rib of orthotropic plat with transverse one in single-layer orthotropic

plate:

SNiP 2.05.03-84 Page 192 a) longitudinal rib goes through V-shaped cut with mouldings at the ends of 15-20 mm in radius in the web of transverse rib, and welded

to the web by two fillet welds from one side

2.2 2.4

b) longitudinal rib goes through the cut in the web of transverse rib and in bearing plate, and welded to it by fillet welds

1.3 1.5

18. Ditto, in two-layer orthotropic plate: a) tee-shape longitudinal rib is connected with transverse one by

high-tension bolts through the holes drilled in the flange of longitudinal rib and in the chord of transverse one.

1.2 1.3

b) tee-shape longitudinal rib is connected with transverse one with the help special clips

1.1 1.2

19. By the main metal of steel plates and longitudinal ribs of orthotropic deck by the border of joints in the zone of all-welded

field butt joint of orthotropic plate:

a) in case of combined in one section butt joints of steel plates and longitudinal ribs, without mechanical treatment of joint

strengthening

2.2 2.5

b) with longitudinal rib butt joints separated from the steel plate butt joint, without mechanical treatment of joint strengthening

2.2 2.4

c) with longitudinal rib treated butt joints separated from the steel plate butt joint, with mechanical treatment of joint strengthening

from the reverse side of steel plate butt joints

2.1 2.3

20. Ditto, in combined butt joint – welded one of steel plate and bolted one in ribs:

a) with arrangement of rectangular rounded cuts in longitudinal ribs, without full penetration of their end parts, without mechanical

treatment of strengthening of steel plate butt joint

2.8 3.1

b) with arrangement of finished semi-circle mouldings in longitudinal ribs, with full penetration of their end parts, with

mechanical treatment of joint strengthening from reverse side of steel plate butt joint

2.1 2.3

c) with break of longitudinal ribs nearby butt joint of steel plate and placing of inserts between their end faces, without mechanical

treatment of strengthening of steel plate butt joint

1.9 2.1

Notes: 1. mf – coefficient that allows the influence of displacements by the contact of members to be connected ant taken as per the table 3 depending on the number of transverse rows of bolts n in the connection.

2. Parameter of n is determined: by the number of transverse rows of bolts in fixing of the given member to the joint plate or fish plate, when this member is broken in

the given node (item 3, d, e, f); total number of transverse rows of bolts in fixing of joint plate to the continuous member (item 3, c).

Dwg. 1. Position of reference section A-A to be checked for endurance by the main metal in the net sections by the connection bolts of composed members and at the free hole as well

Dwg. 2. Position of reference section A-A to be checked for endurance by the main metal in the net sections at the hole with high-tension bolts installed inside tightened with standard force

Dwg. 3. Position of reference section A-A to be checked for endurance by the main metal in the gross section by the first row of high-tension bolts in fastening of join plate to the chords of continuous beam and members of lattice trusses which are not butt connected in

the given node Dwg. 4. Position of reference section A-A to be checked for endurance by the main metal in the gross section by the first row of high-

tension bolts in fastening to the node or in the butt joint of double-web members Dwg. 5. Position of reference section A-A to be checked for endurance by the main metal in the gross section by the first row of high-

tension bolts in fastening to the node or in butt joint of double-web members with single-side cover plate

SNiP 2.05.03-84 Page 193 Dwg. 6. Position of reference section A-A to be checked for endurance by the main metal in the gross section by the first row of high-

tension bolts in the fastening to the node or in butt joint of single-web members with single-side cover plate Table 2

Effective coefficients of stress concentration βs for the design on endurance of steel cables of suspended, back-stayed and prestressed steel spans

Table 2 Devices, which fix or deflect the cables Coefficients βs

1. Wedge anchors 1.1 2. Anchors with grouting of the cable end with the alloy of non-ferrous metals of epoxy compound in conical or cylindrical cavity of the body

1.3

3. Anchors with flattering of round wires ends, restraint of them in anchor plate and filling of voids with epoxy compound with the filler from steel shot

1.1

4. Back-up devices, including tie rods, clips, which have a round contour of the bed, rounding with radius 5 mm at the side faces (in places of cable exit) and clamping strap shortened by 40 mm (in comparison with the bed length):

in case of direct contact of the cable 1.2 with steel bed and lateral pressure equal to q = N/r ≤ 1 MN/m (1 tf/cm) in case of contact of cable with steel bed through soft gasket with the thickness t ≥ 1 mm and lateral pressure equal to q = N/r ≤ 2 MN/m (2 tf/cm)

1.2

5. Hanger ropes clamps; tie rods and clips without cable deflection under lateral pressure

q = N/r ≤ 1 MN/m (1 tf/cm) and direct contact with the cable

1.1

q = N/r ≤ 2 MN/m (2 tf/cm) and contact with the cable through soft gasket t ≥ 1 mm thick

1.1

In Table 2 the following is designated: N – force in the cable, MN (tf); r – radius, m (cm), of the cable deflection line in back-stay devices

Table 3 N 1-3 4-6 7-8 9-10 11-15 16 and more mf 1.00 1.05 1.12 1.16 1.20 1.23

APPENDIX 18*

Compulsory

DESIGN OF ROADWAY ORTHOTROPIC SLAB FOR STRENGTH AND STABILITY 1. The method of design of orthotropic slab should consider combined work of deck plate, ribs supporting it and main

beams.

SNiP 2.05.03-84 Page 194

2. Orthotropic slab is allowed to be conventionally divided to separate systems – longitudinal and transverse ribs with corresponding sections of the deck plate (see drawing).

Box Girder a – longitudinal section; b – plan; c - cross section; d – rib of the bottom slab;

1, 2, 3, …i – number of the top slab cross rib Forces in Orthotropic Slab when Working in Bending Between Main Beams

3. Bending moments in longitudinal ribs of orthotropic slab shall be calculated by formula Msl = M1 + M, (1)

M1 – bending moment in separate longitudinal rib of gross section that includes the adjoining parts of deck plate of general width equaled to the distance a in between longitudinal ribs (see dwg., c), which is considered as a continuous beam on the rigid supports;

the moment is defined from the load located directly above this rib; M – bending moment in section of support of longitudinal rib under the bending of orthotropic slab between main beams, determined

under the action of multispan beam on the rigid supports. Within the extreme thirds of the motor roadway orthotropic slab width and in orthotropic slab of single-track railway

deck spans M shall be equal to 0. Ordinates of influence surface for calculation of bending moment M in the section of support of longitudinal rib above

the “middle” cross rib l (see dwg., a) shall be calculated by formula where

M1i – ordinates of influence line of bending moment in the section of support of longitudinal rib above “middle” cross rib l if the load

is located above the cross rib i; l – span of longitudinal rib (see dwg., b);

L – span of cross rib (see dwg., c); u – coordinate of load position from the beginning of cross rib.

Table 1 Number of cross rib i

Ordinate of influence line M1i/l if z is equal to

0 0.1 0.2 0.5 1.0 1 0 0.0507 0.080. 0.1305 0.1757 2 0 -0.0281 -0.0400 -0.0516 -0.0521 3 0 0.0025 -0.0016 -0.0166 -0.0348 4 0 0.0003 0.0016 0.0015 0.0046 5 0 -0.0001 0 0.0014 0.0025 6 0 0 0 0.0001 0.0012

In Table 1 the following is designated: z – parameter characterizing flexural rigidity of orthotropic slab and determined by formula

where

Isl – inertia moment of gross section of longitudinal rib relatively horizontal axis y1 (see dwg. c); a – distance between longitudinal ribs;

Is – inertia moment of gross section of cross rib – with adjoining part of deck plate 0.2L wide, but not more than l – relatively horizontal axis x1 (see dwg, a).

Note: In Table 1 the following numeration of cross ribs i is accepted: ribs 2-6 are positioned at the distance l from each other in each side from the “middle” cross rib 1 (see dwg., a).

4. In railway span structures deck plate of roadway orthotropic slab shall be designed for bending, but, in so doing, the deck plate bending is not to be checked.

*)2(,sin211 l

uMLaM iiu π=

,0616.0 3

4

s

sl

aII

lLz ⋅=

SNiP 2.05.03-84 Page 195 When arranging track on the ballast the greatest values of bending moments in the deck plate above the longitudinal ribs

shall be determined by formulae: In the zone under the rail

My = - 0.1 va2; (3) In the zone by the axis of deck

My = - 0.08 va2; (4) where

v – load to the unit of length, taken as per item 2 of Compulsory Appendix 5*. Design of Orthotropic Slab Members for Strength

5. For checking the strength of orthotropic slab members it is necessary to get normal stresses in deck plate, longitudinal and cross ribs by means of calculations in the assumption of steel flexible deformations in sections I, II, III and points A, B, C, A1, B1, D1, shown in the drawing, as well as tangential stresses in the deck plate caused by bending of orthotropic slab between main beams

σxp, σyp and τxyp and its combined work with main beams of the deck σxc, σyc and τxyc. 6. Strength of outer bottom fiber of longitudinal rib tensioned at the orthotropic slab bending shall be checked in the zone of negative moments of continuous main beams in the section I-I at the center of the span l of the middle longitudinal rib (see dwg., a

– Point A) by formula where

Ry, Ryn – design and normative resistance of longitudinal rib metal; m –coefficient of working mode, taken as per Table 60*;

m1, m2 – coefficients of working mode; for highway and city bridges as well as for highway portion of combined bridges, coefficients shall be taken as per Table 2; for railway and pedestrian bridges as well as railway portion of combined bridges m1 = 1/∂; in so doing,

check by formula (6) is not required. χ1 – coefficient of influence of initial residual stresses, taken as χ1 = 0.9 – for the outer bottom fiber of longitudinal rib, made of strip,

angles or tees, and χ1 = 1.1 – for longitudinal rib in the form of welded tee; ψ,∂ - coefficients defines by items 4.28* and 4.26.

Table 2* σxc/σxp Values of coefficients m1, m2 for strip ribs

m1 m2 0 0.55 1.40

0.25 0.40 1.50 0.45 0.25 1.60 0.65 0.13 1.60

Note: Coefficients m1, m2 for intermediate values σxc/σxp shall be determined by linear interpolation. 7. Strength of the outer bottom fiber of longitudinal rib compressed at the local bending of orthotropic slab shall be

checked in the zone of positive moments of continuous main beams in the section of support II-II of the middle longitudinal rib (see dwg. a – Point B) by formula

where

ψ, ∂ - coefficients defined as per items 4.28* and 4.26*; χ2 – coefficient of influence of initial residual stresses, taken as χ2 = 1.1 – for the outer bottom fiber of rib, made of strip, angles or

tees, and χ2 = 0.9 – for the rib in the form of welded tee; m –coefficient of working mode, taken as per Table 60*;

8. Strength of the outer bottom fiber of transverse beam shall be checked in the section III-III at the middle part of its span (see dwg. c – Point C) by formula

)5(;11 mRm yxpxc ≤+ σχψσ

)6(,2 mRm ynxpxc ≤+ σσ

)7(,2 mRyxp

xc ≤∂

+σ

χψσ

SNiP 2.05.03-84 Page 196

where ∂ - coefficients defined as per formulae (143) and (144); m –coefficient of working mode, taken as per Table 60*;

9. Strength of the deck plate shall be checked in Points A1, B1, D1 (see dwg. b) by formulae: where

σx = σxc + m4 σxp; σy = σyc + m4 σyp; τxc = τxyc + τxyp;

m –coefficient of working mode, taken as per Table 60*; m3 – coefficient equal to 1.15 when σy = 0 or 1.10 when σy ≠ 0;

m4 – coefficient of working mode equal to 1.05 when checking the strength of deck plate in Point A1 of orthotropic slab of highway and city bridges, and 1.0 – in all other cases.

When making this check it is allowed to take loads as design ones under which one of the stresses acting in the given point of orthotropic slab σx, σy or τxy achieves its maximum value.

Design of Orthotropic Slab Members for Stability 10. Local stability of deck plate between longitudinal ribs, of longitudinal strip ribs, overhang of chords of tee longitudinal and cross ribs shall be provided as per items 4.45* and 4.47*, but local stability of tee ribs webs – as per Compulsory Appendix 16*.

In so doing, the most unfavorable combination of stresses due to orthotropic slab bending between main beams and combination of its collaboration work with deck main beams should be selected.

11*. The general stability of deck plate, supported by longitudinal ribs, shall be provided by cross ribs. The inertia moment of cross ribs Js (see item 3) of compressed (compressed-bent) orthotropic slab shall be calculated by

formula

where α - coefficient defined by Table 2, a*;

ψ - coefficient equal to 0.055, if k = 1; 0.15, if k = 2; 0.20, if k ≥ 3; k – number of longitudinal ribs of orthotropic slab under calculation;

L – distance in between main beams webs or node centers of geometrically unchangeable cross bracings; l – distance in between cross ribs;

Jsl – inertia moment of cross rib full section (see item 3); σxc – acting stresses in deck plate due to collaboration work of orthotropic slab with deck main beams, calculated in the assumption of

steel elastic deformation; σx, cr, ef – stress calculated as per Table 68* by the value σx, cr = σxc .

Table 2a* ω 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.95 1 α 0 0.016 0.053 0.115 0.205 0.320 0.462 0.646 0.872 1.192 1.470 2.025

It is also allowed to calculate σx, cr, ef by formula

)8(,mRyyp ≤

∂

σ

)9(;3 3222

yxyyyxx mRm≤++− τσσσσ)10(,mRsxy ≤τ

*)11(,)1(,,

3

efcrx

xcsls J

lLkJ

σσ

αψ

+=

SNiP 2.05.03-84 Page 197

Note: Coefficient ω is calculated by formula ω = σxc/ϕ0Ry, where ϕ0 shall be defined by Table 3 of item 12, if lef = l. For compressed orthotropic slab, which doesn’t take up local load, the coefficient α in formula (11)* shall be equal to

2.025 that provides the equality of design length lef of longitudinal ribs and the distance between cross ribs l. 12*. Design for general stability of orthotropic slab in whole (compressed or compressed-bent), providing condition (11)*,

shall be calculated by formula

where σxc – see item 11*;

ϕ0 – coefficient of longitudinal bending taken as per Table 3* depending on flexibility λ0; m – coefficient of working mode taken as per Table 60* of item 4.19*.

Flexibility shall be calculated by formula

where lef – designed (free) length of longitudinal ribs determined by expression

Coefficient ω is defined as per Table 2a* by the value

Js, Jsl and l – see item 3; a – distance between longitudinal ribs;

th – thickness of deck plate; ξ - coefficient equal to 1.0 – for orthotropic slab of the bottom chord, and taken as per Table 4* for the top chord slab of the box main

beams; A – area of longitudinal rib full section;

- (here Jt – inertia moment of longitudinal rib full section under the pure torsion). Compressed-bent orthotropic slab of railway bridges shall be checked for general stability by formula (167), taking the flexibility as

per formula (13)*, when ξ = 1.0. Table 3*

Flexibility λ0, λ1 Coefficient ϕ0 for steel qualities 16 Cu 15CrSiNiCu 10CrSiNiCu,

390-14Mn2NVCu, 390-15Mn2NVCu,sk

0 1.00 1.00 1.00

.2

2

,, lAEJ

sl

slefcrx

πσ =

*)12(,0 mRyxc ϕσ ≤

*)13(,

2011

4230

+

+

=

Ll

Llt

aJ

Al

efefhsl

ef

ξλ

.1ω

llef =

;)1(

1 3

ssl

JLl

Jk

+=

ψα

3

5.51

h

t

atJ

+=θ

SNiP 2.05.03-84 Page 198

41 1.00 1.00 1.00 44 1.00 1.00 0.96 50 1.00 0.92 0.88 53 1.00 0.87 0.83 60 0.95 0.76 0.72 70 0.83 0.64 0.59 80 0.73 0.56 0.49 90 0.64 0.50 0.43

100 0.59 0.44 0.38 110 0.53 0.39 0.33 120 0.47 0.34 0.28 130 0.41 0.30 0.25 140 0.36 0.26 0.22 150 0.32 0.23 0.20 160 0.29 0.21 0.17 170 0.26 0.19 0.16 180 0.23 0.17 0.14 190 0.21 0.15 0.13 200 0.20 0.14 0.11

Table 4* f/i Coefficient ξ 0 1.00

0.01 0.75 0.05 0.70 0.10 0.66

f – deflection of longitudinal rib between cross ribs; i – radius of inertia of longitudinal rib full section.

13. Tee longitudinal ribs (see dwgs., c, d) of compressed orthotropic slab of box main beams bottom chord in case of bending-torsional form of loss of stability shall be calculated by formula (12)*, taking the coefficient of longitudinal bending ϕ0

depending on flexibility λ1. Flexibility λ1 shall be calculated by formula

where Ip = Iy + Iz + A (hw-e)2;

l – see item 3; hw – height of rib web with the thickness tw (see dwg., d);

e – distance from the gravity center of the flange with the width bf and thickness tf to the gravity center f tee longitudinal rib (see dwg., d);

Iy, Iz – accordingly inertia moment of section of tee longitudinal rib relatively horizontal axis y and vertical axis z;

)14(,04.0 221

tzw

p

IlIIhI

l++

=ω

λ

SNiP 2.05.03-84 Page 199

For provision of local stability of tee section members of longitudinal rib the thickness of flange and web shall meet the requirements of item 4.45*:

if bf > 0.3 hw the longitudinal rib of full section shall be considered as a I-beam, if bf =0 – as a I-beam; if 0 < bf ≤ 0.3 hw the requirement to the web thickness are defined by linear interpolation between norms of I-beam and

T-beam (bf =0).

APPENDIX 19

Compulsory

ALLOWANCE FOR CREEP, VIBROCREEP OF CONCRETE AND COMPRESSION OF TRANSVERSE JOINTS IN COMPOSITE STRUCTURES

1. When considering concrete creep in statistically determinate structures it is necessary to define stresses balanced within longitudinal section (further – internal stresses) and relative deformations.

For structure which consists of solid web steel girder and reinforced slab integrated with it at the level of roadway (see the drawing), internal stresses due to creep of concrete in general case shall be calculated by the following formulae:

at the level of gravity center of concrete part of the section (tension)

in extreme fiber of steel girder bottom chord (tension or compression)

in extreme fiber of steel girder upper chord (compression)

in the end row bars of slab unstressed reinforcement when Er = Ers = Est (compression) loss of prestressing of stressed reinforcement (compression)

in extreme fiber of concrete (tension)

Relative deformations due to concrete creep in the level of gravity center of its section (see the drawing) shall be calculated by the following formulae:

relative deformations reacting to stresses in steel part of the section

;

).(31

;36144

33

3333

wwff

wwfft

wwffw

thtbA

thtbI

htbtI

+=

+=

+=

)1(;1, bkrb ασσ −=

)2();1(,1

,,,1

sts

stb

stbkrbkrs W

ZA

A −= σσ)3();1(

,2

,,,2

sts

stb

stbkrbkrs W

ZA

A += σσ

)4();1(,

,,,

strf

stb

stbkrbkrr W

ZA

A += σσ

)5();1(1

,

,,,

stp

stb

stbkrb

rkrp W

ZA

An

+= σσ)6(.1)( ,1,, krsbf

bbfkrbf n

σσβασ −+=

)7(;1,

b

bkrb E

σβε =

SNiP 2.05.03-84 Page 200

relative deformations reacting to stresses in concrete part of the section

In formulae (1) – (8): α, β, v – parameters concerning the flexibility of concrete and steel parts of the section and determined by the expressions:

ϕkr = γfEbcn – the limiting characteristic of concrete flexibility; γf - taken as per Table 8;

cn – normative deformation of concrete flexibility determined as per the item 3.15 and Compulsory Appendix 11*, when refined considering requirements of Compulsory Appendix 13*;

σb1, σbf,1 – the initial compression stress at the level of section gravity center and in the end fiber of concrete accordingly due to dead loads and actions;

σsbf,kr - conditional stress in the level of the end concrete fiber, determined by expression Ast, Ist, Ws1,st, Ws2,st, Wrf,st – area, moment of inertia, moments of resistance of bottom and upper beam chords and edge row of gross

reinforcement of section steel part, including reinforcement, accordingly; nr = Est/Erp – reduction coefficients as per the item 5.16.

Other designations correspond to the items 5.5, 5.19* and the drawing. 2. Creep of concrete shall be considered by introduction to the calculation of conventional modulus of elasticity of concrete Eef,kr, if in statistically determinate structures all dead loads are applied in one stage and by the same scheme of behavior. The modulus

Eef,kr shall be calculated by formula

where v, ϕkr – see the item 1. Internal stresses resulting from concrete creep for the i-fiber of section shall be calculated by formula

σi,kr = σi,ef - σi, (10)

where σi,ef,σi – stresses due to dead loads, resulted when elasticity modulus of concrete is Eef,kr and Eb accordingly. Diagrams of relative deformations and internal stresses due to concrete creep 3. When considering concrete creep in statistically determinate structures it’s necessary to determine internal stresses and

external force factors (support reactions, bending moments, etc.) and appropriate deformations. Internal stresses and external force factors may be calculated by the method of successive approximations, taking as

loads the force σb,krAb in the gravity center of concrete part section (here σb,kr and Ab are taken as per the item1). In so doing, while making calculations by the method of forces, the concrete part of sections shall be considered as

follows: with modulus Eef,kr (see the item 2) – when determining main and secondary displacements; with modulus Eb – when determining stresses in the gravity center of concrete arising due to external force factors, caused by creep. Values of limiting

characteristic of creep, used for determination of in σb,kr and Eef,kr in successive approximations and expressed as a ϕkr are shown in Table.

)8(.,,

b

krbkrb E

σξ =

;15.0 ++

=vkr

kr

ϕϕ

α

);1(2,

st

stb

stb

b

IZ

AnAv +⋅=

);1( ,,,,

st

stbfstb

stbkrbkrsbf I

ZZA

A −= σσ

)9(,15.0)1(

15.0, b

krkr

krkref E

vvE

++++−

=ϕϕ

ϕ

SNiP 2.05.03-84 Page 201

Value of limiting characteristic of concrete creep ϕkr when calculating

The number of approximation

Stresses due to concrete creep on the level of gravity center of concrete part section σb,kr

Main and secondary displacements

1 ϕkr 0.5ϕkr

2 0.5ϕkr 0.38ϕkr

3 0.38ϕkr 0.32ϕkr 4. Deflections of structures caused by creep of concrete shall be determined considering the steel part of section as being

under the action of forces σb,kr Ab applied at the level of gravity center of concrete section. The equality σkr = σb,kr is used for statistically determinate structures; for statistically indeterminate systems σkr is equal to the sum of internal stresses and stresses from

external force factors, caused by the creep. 5. Compression deformations of precast reinforced slab transverse joints filled up with concrete shall be considered in calculations if slab longitudinal reinforcement is not butted in joints and the slab, in so doing, has no prestressing in longitudinal

direction. Compression deformations of transverse joints shall be considered by introduction to expressions for α,β, Eef,kr (see

items 1 and 2) of summarized characteristic of concrete creep and compression of transverse joints ϕkr defined by formula

where L – length of reinforced slab compressed by dead loads and constant actions;

Σ∆d – summarized deformation of transverse joints compression located in the length L; ϕkr – is taken as per the item 1;

Eb, Rb – are taken as per items 3.24* and 3.32; When experimental data are not available the value of ∆d, cm, may be calculated by formula

∆d = 0.005 + 0.00035bd, (12) where

bd – width of joint (gap in between end faces of precast slabs). 6. Concrete vibrocreep shall be considered by introduction to the calculation of relative concrete elasticity modulus Evkr

calculated as per the item 2, replacing ϕkr with ϕvkr , and calculated by formula

where ρ1=σmin,1/σmax,1 – characteristic of the cycle of initial stresses in concrete calculated without regard for vibrocreep and creep;

ϕkr, cn – are taken as per the item 1;

APPENDIX 20

Compulsory

DETERMINATION OF STRESSES IN COMPOSITE BEAMS DUE TO CONCRETE SHRINKAGE AND TEMPERATURE ACTIONS

)11(,2.0, LR

E

b

dbkrdkr

Σ∆+= ϕϕ

)13(,)1035.0388.0()1(12 6

111

1bnkrvkr Ec −⋅−⋅−+

+= ρϕ

ρρ

ϕ

SNiP 2.05.03-84 Page 202 1. Stresses in steel and concrete for the statistically determinate structure consisting of solid-web girder, and integrated with it in the level of reinforced slab roadway, shall be determined by formulae

a) due to concrete shrinkage

where Astb,shr, Istb,shr – area and gross inertia moment of composite beam cross section which are reduced to steel, when the modulus of

concrete elasticity is Eef,shr defined as per the item 5.9; Ast – area of steel part section, including composite slab reinforcement;

Sshr = Ast,stb; Zst,stb – distance from the gravity center of Astb,shr to the gravity center of Ast;

Z - distance from the gravity center of Astb,shr to the fiber wherein σshr (positive direction of the axis Z is taken downward) is defined; vshr = 0, vshr = 1 - when stresses in concrete and steel accordingly are determined;

E –is taken as being equal to when determining stresses: in concrete – Eef,shr; in steel girder – Est;

in unstressed reinforcement – Ers; in stressed reinforcement – Erp;

εshr – limiting relative deformation of concrete shrinkage taken as per the item 5.9; b) due to concrete actions

where α = 1·10-5 degree-1 – coefficient of linear expansion of concrete and steel;

tmax = γf tn,max

γf - is taken as per Table 17*; tn,max – is taken as per the item 5.10;

E - is equal to Eb, Est, Ers, Erp when determining stresses in concrete, steel girder, unstressed and stressed reinforcement accordingly; Astb,t, Istb,t - area and gross inertia moment of composite beam cross section which are reduced to steel;

Z - distance from the gravity center of Astb,t to the fiber wherein σr is defined;

In cases of increase or decrease of structure steel part temperature in the formula (2) the following shall be taken: where bsl, tsl, cm, are taken as per the item 5.15.

Values vti and v’ti referred to the i-point of the section where stresses are determined shall be taken as per the item 5.10. Other symbols used in formulae (3) - (6) correspond to the item 5.5 and Drawing 14.

2. When designing of statistically indeterminate structures for temperature action and concrete shrinkage the geometrical characteristics of the section shall be taken according to the item 1.

APPENDIX 21

Compulsory

)1(),(,,

shrshrstb

shr

shrstb

stshrshr vZ

IS

AAE −+= εσ

)2(),(,,

max vZIS

AAEt

tstb

t

tstb

tt −+= ασ

)5(];)50

1(1[17 3sl

b

slt

tnbA −−=

)6();8(17

, −−= stbbfb

slt Z

nbS

'tivv =

SNiP 2.05.03-84 Page 203

DISTRIBUTION OF SHEARING FORCE ABOVE INTEGRATION JOINT OF REINFORCED CONCRETE SLAB AND STEEL STRUCTURE IN COMPLICATED

CASES OF ACTIONS 1. Distribution of end shearing force SeN shall be taken by triangle asymmetrical diagram with the base length ae (see

drawing). In so doing,

where s′1N, s1N – intensity of running shearing forces in accordance with the drawing;

SeN, ae - are taken as per Items 5.28 and 5.29; 2. When determining near-support shearing force caused by SpQ it shall be taken that intensity of relative running shearing forces is changed in both directions by the straight-line diagram from the midlength of near-support section (see the drawing); in so

doing, the ordinate in the middle of near-support section is equal to:

3. The distribution of local concentrated shearing forces (caused by anchoring of high-tensile reinforcement, adjoining of stays or brace etc.) ScN in zones distanced from the slab ends shall be taken by symmetrical triangle diagram with the base length 2ae

(see the drawing); 4. Lengths of designed sections shall be taken (see the drawing) as follows: I = 0.18 (H+bst); II = 0.36 (H+bst) – for the end parts and in places of concentrated forces application as well as in places adjoining the given section; III ≤ 0.8 (H+bst); IV ≤

1.6 (H+bst) – at the rest span length in the end and middle quarters of the span accordingly, when determining shearing forces.

APPENDIX 22

Compulsory

STRENGTH DESIGN OF INTEGRATION OF REINFORCED CONCRETE AND STEEL BY FLEXIBLE STOPS AND ANCHORS

1. Shearing force Sh fallen at the one flexible stop shall meet the following strength conditions: for flexible stops in the form rolled channel, I-beams, angles without strengthening ribs

for flexible stops in the form of round bars when 2.5 < l/d ≤ 4.2

for flexible stops in the form of round bars when l/d > 4.2

besides, for flexible stops in the forms of round bars the following requirement shall be also met In formulae (1)-(4):

)1(,;5.0 1

'1

e

eNN

e

eNN a

Ssa

Ss ==

)2(.15.1

e

pQpQ a

SS =

)1(;,)5.0(55

;,10)5.0(55.0

+≤

+≤

kgfRbttS

kNRbttS

bdrwfrh

bdrwfrh

)2(;,24

;,1024.0

≤

≤

kgfRldS

kNRldS

bh

bh

)3(;,100

;,102

2

≤

≤

kgfRdS

kNRdS

bh

bh

)4(.,63.0

;,063.02

1

21

≤

≤

kgfmRdS

kNmRdS

y

y

SNiP 2.05.03-84 Page 204

tfr – the sum of rounding radius and the biggest thickness of rolled shapes flange, cm; tw – thickness of rolled shapes web, cm;

d - diameter of flexible stop or anchor bar; bdr – the concrete area width sheared by the stop, cm;

Rb, Ry, m – are taken as per the item 5.19*. 2. Shearing forces Sh, fallen at the one inclined anchor made of reinforcing steel of round section (smooth or deformed

bars), or to the one branch of loop anchor shall meet the following requirements where

Aan – cross section area of anchor bar or anchor branch, cm2; α - anchor inclination angle to the surface of steel structure.

For anchors inclined in plan, the product of cos α cos β shall be substituted for cos α in formulae (5) and (6), where β - the angle between anchor horizontal projection and direction of shearing force action.

Shearing force taken up by the compressed inclined anchors shall not exceed 25 % of the total shearing force which acts on the section to be designed.

3. When reinforced part is integrated with the steel one with the help of inclined anchors from strip steel having the thickness tan from 8 mm to 20 mm and width from 20 mm to 80 mm, shearing force Sh fallen at the one anchor or one branch of loop

anchor shall be checked by formula (5) substituting d2 by the expression (where tan is given in cm), and by formula (6).

4. If inclined or horizontal anchors are positioned in the high reinforced concrete rib and used for taking up of main tensile

stress in it, tensile force in inclined anchors shall be determined like in reinforcement bending of standard reinforced concrete, but in vertical anchors - like forces in stirrups of standard reinforced concrete. It is allowed to check independently the sufficiency of anchor

section to take up this tensile force and shearing force in between reinforced concrete and steel, and not sum up the forces. Legend:

_______ maximum values ------------- minimal values

Diagrams of running shearing forces in between reinforced concrete and steel parts I, II, III, IV – design length of sections a.

APPENDIX 23

Compulsory

STRENGTH DESIGNS OF INTEGRATION OF REINFORCED CONCRETE AND STEEL BY HIGH-TENSION BOLTS REDUCING REINFORCED CONCRETE

1. The high-tension bolt tightening force shall be calculated by formula

where Nhb,n – controlled bolt tightening force;

∆N – losses of tightening forces due to shrinkage and creep of concrete and mortar layer under the slab.

anan At

)5(;,sin100cos

;,sin10cos1.02

2

+≤

+≤

kgfRdmRAS

kNRdmRAS

byanh

byanh

αα

αα

)6(;),sin8.0(cos

;),sin8.0cos(1.0

+≤

+≤

kgfmRASkNmRAS

yanh

yanh

αα

αα

)1(,, NNN nhbhb ∆−=

SNiP 2.05.03-84 Page 205

When designing construction of bolt integration as per the drawing the losses shall be calculated by formula where

t ≤ 50 cm – the summary thickness of slab and mortar layer by the hole axis. 2. In frictional connection of reinforced slab with steel chord (through the layer of sand cement mortar or in direct contact)

under the condition of chord cleaning, the shearing force fallen at the one high-tensile bolt shall meet the following requirement where

Nnb - high-tension bolt tightening force taken as per the item 1; k = 1.3 – safety factor;

f – coefficient of friction equal to: 0.60 – if the joint is filled with cement sand mortar, or use of cast-in-situ reinforced concrete slab;

0.45 – in direct contact of precast reinforced concrete and steel. Structure of bolt integration

high-tensile bolt 22 or 24 mm in dia; 2 - concrete hole 50 mm in dia; 3 –reinforcement cage from deformed bars 10 mm in dia; 4 – distribution pad with dimensions 100 x 100 x 16 for bolts 22 mm in dia, and 100 x 100 x 20 for bolts 24 mm in dia.

APPENDIX 24

Compulsory

DESIGN RESISTANCE OF BASE SOIL TO AXIAL COMPRESSION 1. Design resistance of soil base to axial compression R, kPa (tf/m2) under the base of shallow foundation or foundation

from sunk well shall be calculated by formula where

R0 – conventional soil resistance, kPa (tf/m2), taken as per Tables 1-3; b – width (the least side or diameter) of foundation base, m; b = 6 m, if the width is more than 6 m;

d – the depth of foundation laying, m, taken as per the item 2; γ – design value averaged by layers, of soil specific weight laid above the foundation base, and calculated without regard for buoyant

action of water; it is allowed to take γ =19.62 kN/m3 (2 tf/m3); k1, k2 – coefficients taken as per Table 4.

The value of conventional resistance R0 for hard sandy loam, loam and clays (IL < 0) shall be calculated by formula R0 = 1.5 Rnc

and taken for, kPa (tf/m2): sandy loams – not more than 981 (100); loams – 1962 (200); for clays – 2943 (300), where

Rnc – ultimate strength for uniaxial compression of clay soil sample of natural humidity. Design resistance of the base from unaerated rocks R, kPa (tf/m2) shall be calculated by formula

where

γg – soil safety factor equal to 1.4; Rc - ultimate strength for uniaxial compression of rock sample, kPa (tf/m2).

If bases consist of weakly aerated, aerated or heavily aerated rocks being homogeneous by the depth, their design resistance to axial compression shall be calculated using results of soil static plate-bearing tests. If these results are unavailable it is

)2(),0002523.0(, tNN nhb −=∆

)3(,1nbh fN

kS ≤

[ ]{ } )1(,)3()2(17.1 210 −+−+= dkbkRR γ

)2(,g

cRRγ

=

SNiP 2.05.03-84 Page 206 allowed to take the value R by formula (2) for weakly aerated and aerated rocks taking the value Rc with lowering coefficient equal to

0.6 and 0.3 accordingly; for strongly aerated rocks – as per formula (1) and Table 3 as for large-fragmented soils. 2. When calculating design resistance of soil bases by formula (1) the depth of shallow foundation or foundation from the

sunk well shall be taken as: from the surface of soil near the support on the cut level within foundation line, but in river beds, from the water course bottom near the support after its decrease to the depth of general and the half of local soil washing-out at the design flow rate (see items 1.25* -

1.30) - for intermediate bridge supports; from natural soil surface with increase to the half of the embankment cone height at the front foundation face by the bridge axis – for

buried abutment; from natural soil surface with increase to the half of the minimal embankment height at the studied link – for pipes of closed loop;

from the bottom of chute or foundation cut – for pipes of open loop 3. Design resistance calculated by formula (1) for clays and loams in bridge foundation bases located within the constant

water courses shall be increased to the value equal to 14.7 dw, kPa (1.5dw, tf/m2), where dw the depth of water, m, from the lowest level of low water to the level taken as per item 2a.

Table 1

Conventional resistance R0 of silt-clay (noncollapsible) bases soils, kPa (tf/m2) depending on index of liquidity IL

Soils Porosity coeffici

ent e 0 0.1 0.2 0.3 0.4 0.5 0.6 0.5 343 (35) 294 (30) 245 (25) 196 (20) 147 (15) 98 (10) -- Sandy loams when Ip ≤ 5 0.7 294 (30) 245 (25) 196 (20) 147 (15) 98 (10) -- -- 0.5 392 (40) 343 (35) 294 (30) 245 (25) 196 (20) 147 (15) 98 (10) 0.7 343 (35) 294 (30) 245 (25) 196 (20) 147 (15) 98 (10) --

Loams when 10 ≤ Ip ≤ 15

1.0 294 (30) 245 (25) 196 (20) 147 (15) 98 (10) -- -- Clays when Ip ≥ 20 0.5 588 (60) 441 (45) 343 (35) 294 (30) 245 (25) 196 (20) 147 (15)

0.6 490 (50) 343 (35) 294 (30) 245 (25) 196 (20) 147 (15) 98 (10) 0.8 392 (40) 294 (30) 245 (25) 196 (20) 147 (15) 98 (10) -- 1.1 294 (30) 245 (25) 196 (20) 147 (15) 98 (10) -- --

R0 is determined by interpolation for intermediate values IL and e. If the value of plasticity index Ip is within 5-10 and 15-20, then average values of R0 shall be taken as per Table 1 for sandy loams,

loams and clays accordingly. Table 2

Sandy soils and their humidity Conventional resistance R0 of sandy soils of average density in bases,

kPa (tf/m2) Gravel and coarse soils independently on their humidity 343 (35)

Soils of average coarseness: low-wet 294 (30)

wet and saturated with water 245 (25) Fine soils: low-wet 196 (20)

wet and saturated with water 147 (15) Silt soils: 196 (20) low-wet 147 (15)

wet and saturated with water 98 (10) Note: For tight sands the given values of R0 shall be increased by 100 %, if their density is determined by static sounding, and by 60

%, if their density is determined by results of soil laboratory tests. Table 3

Soil Conventional resistance R0 of sandy soils of large-

SNiP 2.05.03-84 Page 207

fragmented soils in bases, kPa (tf/m2)

Pebbled (crushed) soil from rock debris: crystalline 1470 (150)

sedimentary 980 (100) Gravel (landwaste) soil from rock debris:

crystalline 785 (80) sedimentary 490 (50)

Note: Design resistance R0 values shown in Table 3 are calculated for large-fragmented soils with sand filler. If large-fragmented soils contains more than 40 % of clay filler, then the value R0 for such kind of soil shall be taken as per Table 1 dependently on Ip, IL and e

of the filler. Table 4

Soil Coefficient k1, m-1 k2

Gravel, pebble, coarse gravel sand and of average coarseness

0.10 3.0

Fine sand 0.08 2.5 Silt sand, sandy loam 0.06 2.0

Hard and semi-hard loam and clay 0.04 2.0 Hard-plastic and soft-plastic loam and clay 0.02 1.5

APPENDIX 25*

Compulsory

METHOD OF CHECKING THE CARRYING CAPACITY OF SOIL OF PILED OR

CAISSON FOUNDATION AS CONVENTIONAL SHALLOW FOUNDATION Conventional foundation shall be taken in the form of rectangular parallelepiped. Its dimensions for piled foundation with the

foundation grillage penetrated into the ground shall be determined by drawings 1 and 2, for piled foundations with foundation grillage positioned above the soil by drawings 3 and 4, for caisson foundation by the drawing 5.

Average value, shown in drawings 1-5, of design friction angles φm of grounds, which are cut through by piles, shall be calculated by formula

where φi – design angle of internal friction of the i-ground layer, laid within the depth of pile sinking to the soil;

hi – thickness of this layer, m; d – the depth of pile sinking to the ground from the bottom of foundation grillage or design ground surface, m, which location shall be

taken according to requirements of item 7.10. Carrying capacity of conventional foundation base is checked as per item 7.8*, in so doing, the average p, kPa (tf/m2) and maximum pmax, kPa (tf/m2), which are subject to checking, of the ground pressure in the section 3-4 by the base of conventional

foundation (see dwg. 1-5) shall be calculated by formulae:

where

)1(,d

hiim

ϕϕ

Σ=

)2(;cc

c

baNp =

)3(,)3(

)23(634

1

1max

cb

c

hcc

cc

c

adckb

dFMaba

Np

+

++=

SNiP 2.05.03-84 Page 208 Nc – normal component of conventional foundation pressure to base soil, kN (tf), to be defined with regard of weight of soil mass 1-2-

3-4 together with foundation grillage and piles or caisson embedded in soil mass; Fh, Mc – accordingly, horizontal component of external load, kN (tf), and its moment relatively to the main axis of conventional

foundation horizontal section in the level of design ground surface, kN·m (tf·m), taken as per requirements of item 7.10; d1 – depth of foundation laying in respect of design ground surface, m (see dwg. 1-5);

ac, bc – conventional foundation dimensions in plan in the direction parallel to the plane of loading effect and perpendicular to this plane, m;

k – coefficient of proportionality, that determines increase, with the depth, of coefficient of soil bed, located higher the foundation base, and taken as per Table;

cb – coefficient of soil bed in the level of conventional foundation base, kN/m3 (tf/m3), calculated by formulae: if d1 ≤ 10 m, cb = 10k, kN/m3 (tf/m3);

if d1 > 10 m, cb = kd1. Drawing 1. Conventional piled foundation with foundation grillage, penetrated into the ground when the angle of pile inclination is

less than φm /4. Drawing 2. Conventional piled foundation with foundation grillage, penetrated into the ground when the angle of pile inclination is

more than φm /4. Drawing 3. Conventional piled foundation with foundation grillage, located above the ground when the angle of pile inclination is less

than φm /4. Drawing 4. Conventional piled foundation with foundation grillage, located above the ground when the angle of pile inclination is

more than φm /4. Drawing 5. Conventional caisson foundation

a – without benches; b – with benches Ground Coefficient k, kN/m4 (tf/m4),

Flow plastic clay and loam (0.75 < IL ≤ 1) 490-1960 (50-200) Soft plastic clay and loam (0.5 < IL ≤ 0.75); plastic sandy loam (0 ≤ IL

≤ 1); dust sand (0.6 ≤ e ≤ 0.8) 1961-3920 (200-400)

Non-plastic and semi-hard clay and loam (0 ≤ IL ≤ 0.5); hard sandy loam (IL < 0); fine sands (0.6 ≤ e ≤ 0.75) and mid-coarse sand (0.55 ≤ e

≤ 0.7)

3921-5880 (400-600)

Hard clay and loam (IL < 0); coarse sand (0.55 ≤ e ≤ 0.7) 5881-9800 (600-1000) Gravel sand (0.55 ≤ e ≤ 0.7) and pebble with sand filler 9801-19 600 (1000-2000)

APPENDIX 26

Compulsory

METHODS OF CHECKING THE CARRYING CAPACITY OF SOIL UNDERLYING STRATUM

Soil underlying stratum carrying capacity shall be checked on the base of condition:

Where p – soil mean pressure acting under footing of conventional foundation of shallow

embedding, kPa (tf/m2); γ - mean (by layers) value of designed specific weight of soil located above the top

of underlying stratum; it is allowed to take γ = 1962 kN/m3 (2 tf/m3); d - embedding of shallow foundation footing relative to designed surface of soil, m

,)((n

iRdpzd

γγαγ ≤−++

SNiP 2.05.03-84 Page 209

taken according to compulsory Appendix 4. zi- distance foundation footing to surface of checked underlying stratum of soil, m;

α - coefficient taken as per Table; R - rated resistance of underlying soil , kPa ((tf/m2) determined by Formula (1) of compulsory checked soil layer.

γ - coefficient of safety as per purpose of structure, taken equal to 1.4; Coefficient α is determined by Table in dependence of ratio zi /b for round and

of ratio zi /b and α/b for rectangular in plan foundation. Here α is a large side of rectangular in plan foundation, b – small its side or diameter of round in plan foundation.

Carrying capacity of soil underlying stratum under foundation of piles or caisson shall be checked as under conventional foundation with dimensions taken according to compulsory Appendix 25*.

Coefficient α

Zi b

For rectangular in plan foundation in dependence upon ratio of sides of its footing α / b

For round In plan foundation 1 1.2 1,4 1,6 1,1 2.0 2.4 2.8 3,2 4 5 10 and more

0 1,000 . 1,000 1,000 1,000 1,000 1.000 1,000 1,000 1,000 1,000 1,000 1.000 1,000

0,2 0,949 0,960 0,968 0,972 0,974 0.975 0.976 0,976 0,977 0,977 0,977 0.977 0.977 0,4 0,756 0,800 0,830 0,848 0,859 0.866 0,870 0,875 0,972 0,879 0,880 0,881 0881 0,6 0,547 0,606 0,651 0,682 0,703 0,717 0,727 0,757 0,746 0,749 0,753 0,754 0.755 0,8 0.390 0,449 0,496 0,532 0,558 0,578 0,593 0.612 0,623 0,630 0,636 0,639 0,642 1,0 0,285 0,334 0,378 0,414 0,441 0,463 0,482 0,505 0,520 0,529 0,540 0,545 0.550 1,2 0,214 0,257 0,294 0,325 0,352 0,374 0,392 0,419 0,437 0,449 0,462 0,470 0,477

1,4 0,165 0,201 0,232 0,260 0,284 0,304 0.321 0,350 0,369 0,383 0,400 0,410 0.420 1,6 0,130 0,160 0,187 0.210 0,232 0,251 0,267 0,294 0,314 0,329 0,348 0,360 0,374 1,8 0,106 0,130 1,153 0,173 0,192 0,209 |0,224 0,250 0,270 0,285 0,305 0,320 0,337 2,0 0,087 0,108 0,127 0,145 0,161 0,176 0.189 0,214 0,233 0,241 0,270 0,255 0,304 2,2 0,073 0,090 0,107 0,122 0,137 0,150 0,163 0,185 0,208 0,218 0,239 0.256 0,280 2,4 0,062 0,077 0,092 0,105 0,118 0,130 0,141 0,161 0,178 0,192 0,213 0,230 0,258 2,6 0,053 0,066 0,079 0,091 0,102 0,112 0,123 0,141 0,157 0,170 0,191 0,208 0.239 2,8 0,046 0,058 0.069 0,079 0,089 0,039 0,108 0,124 0,139 0,152 0,172 0,189 0,226 3,0 0,040 0,051 0,060 0,070 0,078 0,087 0.095 0,110 1,124 0,136 0.155 0,172 0,208 3,2 0,036 0,045 0,053 0,062 0,070 0,077 0,085 0,098 0,111 0,122 0,141 0,158 0.190 3,4 0,032 0,040 0,048 0,055 0,062 0,069 0,076 0,088 0,100 0,110 0,128 0,144 0,1 ?4 3,6 0,028 0,036 0,042 0,049 0,056 0,062 0.063 0,080 0,090 0,100 0,117 0,133 0.175 3,8 0,024 0,032 0,038 0,044 0,050 0,056 0,062 0.072 0,082 0,091 0,107 0,123 0,166 4,0 0,022 0,029 0,035 0,040 0,046 0.051 0,056 0,066 0,075 0,084 0,095 0,113 0.158

4,2 0,021 0,026 0,031 0,037 0,042 0,048 0.051 0060 0,069 0,077 0,091 0.105 О.150 4,4 0,019 0,024 0,029 0,034 0.038 0,042 0,047 0,055 0,063 0,070 0,084 0,093 0.144 4,6 0.018 0,022 0,026 0,031 0,035 0,039 0,043 0.051 0.058 0,065 0.078 0,091 0.137 4,8 0,016 0,020 0,024 0,028 0,032 0,036 0 040 0.047

0,054 0,060 0,072 0.085 0,132-

5,0 0,015 0,019 0,022 0,026 0,030 0,033 0,037 | 0,044 0,050 .0,056

0,067 0,079 0,126

APPENDIX 27

Compulsory

DETERMINATION OF ADDITIONAL PRESSURE FROM WEIGHT OF APPROACHED EMBANKMENT ADJOINING PART ONTO BASE OF ABUTMENT

1. Additional pressure to soils of base under rear face of abutment (in level of foundation foot) from weight of approached embankment (see drawing) p’1, kPa (tf/m2) shall be determined by the following formula

)1(111' hp γα=

SNiP 2.05.03-84 Page 210

For buried abutment the additional pressure to soils of base under abutment rear face from weight of abutment cone p’2, kPa (tf/m2)

Pressure p’1 and p’2 shall be determined by summing up according to corresponding foundation faces the pressure from design loads with addition of p’1 and p’2 .

In formulae (1) and (2):

γ - estimated specific weight of filled soil can be taken γ = 17.7 kN/m3

(1.8 tf/m3); h1 - height of embankment, m;

h2 - height of cone above front face of foundation, m; α1, α2 - coefficients taken according to Table 1 and 2, respectively.

Additional pressure from weight of approached embankment onto soils of base for buried embankment 1 – front face; 2 – rear face

2. Relative eccentricity of resultant for loads in level of shallow foundation foot shall be determined as follows:

where: α - foundation foot length, m (see drawing); y - distance from main central axis of foundation foot to more

loaded rib, m; e0, r - same values as in item 7.7*.

Table 1

Depth of Height of Value of coefficient α1 foundation embankment for rear for rear face of abutment embedding h1, m face of at length of foundation foot α , m

d, m abutment up to 5 10 15 5 10 0.45 0.10 0 0 20 0.50 0.10 0.05 0 30 0.50 - 0.06 0

10 10 0.40 0.20 0.05 0 20 0.45 0.25 0.10 0.05 30 0.50 - 0.10 0.05

20 10 0.30 0.20 0.15 0.10 20 0.35 0.30 0.20 0.15 30 0.40 - 0.20 0.15

15 10 0.35 0.20 0.10 0.05

)2(222' hp γα=

)3(,)1( 21

21

pyap

ppre

+−

−=η

SNiP 2.05.03-84 Page 211

20 0.40 0.25 0.15 0.10 30 0.45 - 0.20 0.15

25 10 0.25 0.20 0.20 0/15 20 0.30 0.30 0.20 0.20 30 0.35 - 0.20 0/20

30 10 0.20 0.20 0.20 0.15 20 0.25 0.30 0.25 0.20 30 0.30 - 0.25 0.20

Notes. 1. For intermediate values d, h1 and α the coefficient α1 shall be determined by interpolation. 2. In calculation the deep embedded foundation is considered as conventional limited by contour taken according to compulsory Appendix 25*.

Table 2

Depth of foundation Value of coefficient α2 with height of cone h2 , m embedding, d, m 10 20 30

5 0.4 0.5 0.6 10 0.3 0.4 0.5 15 0.2 0.3 0.4 20 0.1 0.2 0.3 25 0 0.1 0.2 30 0 0 0.1

Note. For intermediate values d, h2 and α the coefficient α2 shall be determined by interpolation.

APPENDIX 28

Recommended

ECCENTRICAL COMPRESSION STRENGTH DESIGN OF CIRCULAR SECTION OF REINFORCED CONCRETE MEMBERS

Strength of eccentrically compressed reinforced concrete members of circular section (see drawing) with untensioned reinforcement equally distributed by periphery (with longitudinal bars number not less than 6) is calculated from the condition

where r - radius of cross section ;

ξcir - relative area of compressed concrete zone, determined as follows:

)1(,)sin(sin32

,

3

scir

totsscir

brbc rARARNe ϕπ

ξππ

ξπη ++≤

SNiP 2.05.03-84 Page 212

when fulfilled the condition N ≤ 0.77 Rb Ab + 0.645 Rs As, tot (2)

from solution of Equation

when condition (2) is not fulfilled from solution of Equation

πξcir - angle in radians (see drawing); ϕ - coefficient considering the behavior of tensioned reinforcement and taken equal to:

when fulfilled the condition (2) ϕ = 1.6 (1 – 1.55 ξcir ) ξcir, but not more than 1;

when condition (2) is not fulfilled ϕ = 0;

As,tot - section area of all longitudinal reinforcement; Rs - radius of periphery coming through gravity centres of rod longitudinal

reinforcement. Eccentricity ec is determined by items 3.52*-3.54* and 3.70*.

For concrete of class above B30 the value Rb is taken as one for concrete of class B30. Drawing. Diagram that is used when calculate circular section of eccentrically compressed member.

APPENDIX 29*

For reference

MAIN LETTER DESIGNATIONS OF VALUES

Section 1. BASIC CONCEPTS

Mu - overturning forces moment Mz - confining forces moment Qr - shearing force Qz - confining force l - designed span h - height

1+µ - dynamic coefficient m - coefficient of behavior conditions γn - safety factor as per purpose γf - safety factor as per load

Section 2. LOADS AND FORCES

)3(;55.2

22sin

,

,

totssbb

cirAbtotss

cir ARAR

RARNb

+

++= π

ξπ

ξ

)4(;22sin

,totssbb

cirAb

cir ARAR

RNb

+

+= π

ξπ

ξ

SNiP 2.05.03-84 Page 213

A - Area P - concentrated vertical load Fh - concentrated horizontal shearing Force M - moment of force G - weight of one car of load АБ G - shear modulus Sf - resistance force due to friction Sh - reactive resistance value for rubber bearing parts T - Period P - intensity of live vertical load from Pedestrians pv - vertical pressure from embankment weight ν - intensity of equivalent load from vertical action of live moving load νh - intensity of horizontal distributed ψ - linear load when determined the pressure to links of pipes u - value to determine intensity of horizontal distributed load cw - aerodynamic coefficient of structure head resistance against wind force kn - coefficient considering the change of wind head depending on height; q0 - intensity of velocity pressure of ε - coefficient considering the absence of railway very heavy trains circulation; γn - characteristic specific weight of soil νvb - specific weight of transported rock vf - maximum set speed λ - length of loading the line of influence α - projection of least distance from top to end of influence line α - total thickness of resin layers in bearing parts

h1,h2 - depth of filling above pipes total thickness of resin layers in D - Diameter R - Radius δ - shift in bearing parts f - rise of arch C - length of contact of load wheel with roadway ϕn - characteristic angle of soil inner friction εn - ultimate relative deformation of concrete shrinkage Cn - specific deformation of concrete creep t - Temperature

tn, T - maximum positive temperature tn, x - least negative temperature t3 - temperature of closure ∆1 temperature deviation z - number of bridge piers in group z - number of installed blocks α - relative position of influence line top α - coefficient of linear expansion η - coefficient of load combination γf - load safety factor cv - coefficient of vertical pressure for sections of pipes

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1+µ , - dynamic coefficients 1+2/3µ

τn - lateral pressure ε - coefficient considering the absence of railway very heavy trains circulation;

s1 - coefficient considering action of live load from other tracks (lanes); s2 - coefficient considering in combined bridges simultaneously the loading of ways of

different purpose; µn - characteristic value of friction factor;

µmax, - maximum and minimum values of µmin friction factor.

Section 3. CONCRETE AND REINFORCED CONCRETE STRUCTURES CHARACTERISTIC OF MATERIALS

Characteristic resistance of concrete

Rbn - against axial compression; Rbtn - against axial tension.

Designed resistance of concrete

when calculated by limit states of first group Rb - against axial compression; Rbt - against axial tension.

when calculated by limit states of second group

Rb,ser - against axial compression; Rbt,ser - against axial tension when calculated the prestressed members by formation of cracks Rb,mc1 - against axial compression when calculated for strength against formation of

longitudinal micro-cracks (mc) when prestressed, transported and installed Rb,mc2 - against axial compression when calculated under performance load by formulas of

resistance of elastic materials (design for common action of force factors and unfavourable impacts of environment);

Rb,sh - against shear when bending. Reinforcement characteristic resistance against tension

Rsn - untensioned; Rpn - stressed.

Reinforcement designed resistance against tension

Rs - untensioned; Rp - stressed; Rsc - untensioned - against compression; Rpc - stressed located in compressed zone.

Elasticity modulus ratio

n1 - taken when designed as per strength and for stressed reinforcement when designed for endurance as well;

n’ - ditto, taken when designed for endurance for untensioned reinforcement members

Geometric characteristic A’b - section area of concrete compressed zone

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Ab - section area of whole concrete; Ared - member reduced section area; Ired - inertia moment of reduced section of member relatively its gravity centre;

Wred - moment of resistance of member reduced section for end tensile fibre; As,A’s - section area of untensioned tensile and compressed longitudinal reinforcement; Ap,A’p - ditto, of stressed reinforcement;

µ - reinforcing coefficient determined as ratio of tensile longitudinal reinforcement section area to cross section area less compressed and tensile overhangs of chords;

b - width of rectangular section, web (rib) width of tee, I- , and box section b’f - width of chord of tee, I- and box section in compressed zone; h - height of section;

h’f - reduced (including haunches) height of compressed chord of tee, I- , and box section h0 - effective height of section; x - height of concrete compressed zone;

αs,αp - distance from gravity centre of untensioned and stressed longitudinal reinforcement, relatively, to nearest face of section

α’s,α’p - ditto, for compressed reinforcement; ec - eccentricity of longitudinal force N relatively centre of gravity of reduced section η - coefficient considering influence of cross bending at eccentric compression (to be

introduced to value ec), taken according to i.3.54*; eo - designed (taking into account coefficient η introduced to value ec) distance from

longitudinal force N to centre of gravity of tensile reinforcement of eccentically compressed section:

e, e’ - distance from longitudinal force N application axis to centre of gravity of tensile and compressed, relatively, reinforcement of eccentically tensioned section;

i - radius of inertia of cross section; r - core distance d - diameter of circular member, nominal dia of reinforcing bars

STRESSES IN THE CONCRETE

σbt - tensile (including losses) stress in concrete of tensile zone of prestressed member under live load;

σmt, σmc

- main tensile and main compression

stresses; σtx, σby - normal stresses in concrete, relatively on longitudinal axis and indirection normal to it;

τb - tangential stresses in concrete. STRESSES IN REINFORCEMENT

σs - stress in untensioned tensile reinforcement under load; σp - total stress in stressed reinforcement of tensile zone under load; σpc - residual stress, introduced into the design, of stressed reinforcement located in

compressive zone: σp s = Rpc - σpcl ; σpcl - designed stress (with deducted all losses) in stressed reinforcement located in

compressive zone . Section 4. STEELWORKS

A - gross section area; Abn - bolt section area, net; An - section area net; Af - flange (chord) section area;

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Aw - web section area ; Awf - section area of fillet angle; Awz - section area of fusion line metal E - modulus of elasticity F - force G - shear modulus Is - rib section inertia moment Isl - longitudinal rib section inertia moment It - beam twist inertia moment

Ix, Iy - inertia moments of gross section relative to axes x-x and y-y, respectively, here and further - x-x is horizontal axes , y-y is vertical axis;

Ixn, Iyn ditto, of net section; M - moment, bending moment Mcr - critical bending moment within effective length of beam compressed chord

determined by theory of thin- walled elastic bars for present conditions of fixing and loading the beam;

Mx, My

- moments relative to ax4es x-x and y-y, respectively;

N - longitudinal force; Ncr - critical normal force determined by theory of thin-walled bars for present conditions

of fixing and loading the members; Q - transverse force, shear force

Qfic - conventional transverse force for connecting members; Qs - conventional transverse force for system of planks located in one plane Rba - foundation (anchor) bolt tension designed resistance; Rbh - high tension bolts designed resistance Rbp - designed resistance against bearing stress of bolt connections; Rbs - bolt shear designed resistance; Rbt - bolt tension designed resistance

Rbun - bolt steel characteristic resistance taken equal to breaking strength σb as per state

standards and specifications for bolts; Rcd - designed resistance against diameter compression of rollers (with free

touching in structures mobility-restricted; Rdh - high-tension wire or cable tension designed resistance Rlp - designed resistance to local bearing stress in cylindrical hinges (journals) at close

touching Rp - steel designed resistance against bearing stress of end face surface (when fit is

present) Rs - steel shear designed resistance Rth - steel tension designed resistance in direction of width of rolled stock Ru - steel designed resistance against tension, compaction, bending as per breaking

strength; Run - steel rupture breaking strength taken equal to minimum value σbas per state standards

and specifications for steel; Rwf - designed resistance of fillets against shear (conventional) by weld metal Rwu - designed resistance of butt welded joints to compaction, tension, bending as per

breaking strength; Rwun - characteristic resistance of weld metal as per breaking resistance

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Rws - designed resistance of butt welded joints to shear Rwy - designed resistance of butt welded joints to compression, tension and bending as per

ultimate yield; Rwz - fillet designed resistance against shear (conventional) as per metalof fusion line; Ry - steel designed resistance against compression , bending as per ultimate yield; Ryn - steel ultimate yield taken equal to value of ultimate yield σT as per state standards and

specifications for steel; S - static moment of sheared part of gross section relatively neutral axis;

Wx,Wy - cross section resistance minimum moments in respect to axes x-x and y-y, relatively; Wxn,W

yn - net section resistance minimum moments in respect to x-x and y-y, relatively;

b - width; bef - designed width; bf - width of flange (chord); bh - width of projected part of web, overhang e - eccenticity of force

frel - relative eccentricity (erel=eA/Wc); eef - reduced relative eccentricity (eef = erel η); h - Height hw - designed height of web (distance between axes of chords;. i - section inertia radius;

imin - section inertia minimum radius; kf - Leg l - length, span lc - outward thrust; ld - diagonal; lef - designed conventional length; lm - length of panel (distance between units of lattice structure; ls - length of plank; lw - length of weld;

lx,ly - designed length of member in planes perpendicular to axes x-x and y-y, respectively; m - behaviour conditions coefficient; mb - behavior conditions coefficient for

connection ; r - radius; t - Depth tf - depth of flange (chord); tw - depth of web

βf,βz - coefficients for design of fillet for weld metal and fusion zone metal, respectively; γn - safety factor for purpose; γm - partial safety factor for material; γu - safety factor in designs for breaking strength; η - influence factor for shape of section ; λ - flexibility (λ=lef/i);

λx, λy - designed flexibility of member in planes perpendicular to axes x-x and y-y, respectively;

ν - steel lateral deformation (Poisson’s) coefficient; σx, σy - normal stresses parallel to axes x-x and y-y, respectively;

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τxy - tangential stress; ϕ - longitudinal bending coefficient;

Section 5. COMPOSITE STRUCTURES ni - reduction coefficient for section i-material

EI,Eij - modulus of elasticity for section i- material with indication of j-type reinforcement; Ii,Iij - inertia moment for section or its parts with indication of belonging to j-design Wij - resistance moment of i-fibre of i- part of section

Ai, Aij - area of section or its elements; zij - distance of i-element of section to j-centre of gravity;

b, bi - width of element or its i-part; ti, tij - depth of i-element of section with indication of j location; tn,

max, - performance and designed maximum

tmax temperature difference M, Mi, - bending moment of behaviour

Mij i-stage for j-designed case; N, Ni, - normal force from outside action or

Nij replacement of section i-part with indication of j-stressed condition of materials making the part under replacement;

Si,Sij - shear force originating from j-type of force or action , with indication of location j (in separate cases with indication of i-type of design;

Sij - intensity of shearing forces on span structure i-part against j-force Ri - designed resistance of i-material of section; Rbt - designed resistance of concrete against axial tension

Rbt,ser - designed resistance of concrete against axial tension when designed prestressed members as per crack formation;

σi, σil, - stresses in section i-material with σij indication self-balanced stresses of section i or location of fibre j under checking

εi, εj - deformation of section i-material or from j-force with indication of j-location as per section;

p cycle characteristic; æj, η - correction factors acting forces;

k - correction factor to deformation value of the concrete ψcr - coefficient considering the behavior of concrete with cracks

m,mi - behaviour condition coefficient for i-material or element of section Pi - specific points of section;

Section 6. WOOD STRUCTURES Nd - designed value of axial force; Md - designed value of bending moment; Qd - Designed value of lateral force; Ndd - designed value of carrying capacity of glued dowel for pulling it out or pressing down

DESIGNED RESISTANCE OF WOOD

Rdb - when bended; Rdt - against tension along fibres; Rds - Against compression along fibres; Rdc - ditto, in glued structures;

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Rdqs - against bearing stress along fibres; Rdq - against compression and bearing stress of all surface across fibres Rdcq - ditto, in glued structures; Rdqp - local bearing stress across fibres; Rdqα - ditto, for element length parts Rdαb - against shear along fibres when bending; R dαm - against shear (indirrect) along fibres R dsm - against shearing across fibres; R qα - against bearing stress and shear at angle α to direction of fibres R dαf - against shear on glued seams along fibres in glue-dowel connections; R dαfα - against shear on glued seam in glue- dowel connections when glued the dowels at

angle α to direction of fibres. Design Areas

Abr - gross cross section; Ant - net cross section; Ad - cross section when checked stability Aα - Shearing Aq - bearing stress

Other Characteristics

Sbr - cross static moment of section part relative to neutral axis Wnt - resistance moment of plane of weakness Ix,Iy - net section inertia moments relative to axes x-x and y-y, respectively x, y - distance from main axes x-x and y- y, respectively to the most far points of section;

l - design span of slab; l - theoretic length of pile l - length of darning; lα - distance between braces of branches in composite members lα - length of block in composite members; lc - design length of member when checking stability l3 - length of bearing stress area of wood along fibres; ld - design length of shearing in connections on blocks lt - length of fixing α - pitch of wheel or track in direction across road; α - clear distance between blocks; α - depth of connection b - width of beam; b - total width of composite member section z - arm of forces shearing the block; d - diameter; dl - diameter of hole for dowel; δ - gap during timber splicing; δ - thickness of one board; t - thickness of most thin among members under connection; t1 - thickness of middle-sized members under connection t2 - thickness of end members under connection; t - thickness of pavement; λ - flexibility of member;

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λ - flexibility of composite member branch λz - reduction flexibility of composite member n - number of cuts in initial connection; nq - number of cuts of braces in one joint; nf - number of joints between branches of members m - behavior condition coefficient mq - ditto, for bearing stress of fibres; mα - for shearing along fibres; ϕ - longitudinal bending coefficient µ2 - flexibility reduction coefficient ; δ - compliance coefficient of connection; ε - coefficient considering the action for stability of additional moment from normal

force.

Section 7. BASES AND FOUNDATIONS Soil characteristic

e - degree of porosity; Il - flow characteristic index; Lp - plasticity number; γ - specific weight; ϕ - Angle of inner friction; Rc - ultimate strength for one-axis compaction of rock samplings; Rnc - ultimate strength for one-axiscompaction of natural moistened clay samplings;

Loads, pressure, resistance

F - force, design value of force M - moment of forces N - force normal to footing of foundation;

p, pmax - mean and maximum pressure of foundation footing onto soil R - design soil resistance R0 - table value of conventional soil resistance

Geometrical characteristics b - Width (smaller side or diameter) of foundation footing: a - Length of foundation footing; A - Area of foundation footing d - Depth of foundation embedding; dw - Depth of water; h - Depth of soil layer or height of Embankment; eo - Eccentricity of loads resultant ; relative to central axis of foundation footing r - Section core radius of foundation near its footing

W - Resistance moment of foundation Footing for less loaded rib z - Distance from foundation footing.

Coefficients γz - soil safety; γn - safety as per structure purpose; γc - behavior conditions.

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SNiP 2.05.03-84 Bridges and Culverts ENG