08-Series 8000 Structures

8/2/2019 08-Series 8000 Structures

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Standard Technical Specification - 2002 Series 8000: Structures

Content

Ethiopian Roads Authority Page 8000-1

SERIES 8000: STRUCTURES

CONTENT

LIST OF TABLES AND FIGURES ................................................................................................ 11

DIVISION 8100: FOUNDATIONS FOR STRUCTURES.................................................................12

8101 Scope ..............................................................................................................................12

8102 Materials .........................................................................................................................12

(a) General ..................................................................................................................12

(b) Rock (for rock fill).................................................................................................12

(c) Crushed stone ........................................................................................................13

(d) Granular fill ...........................................................................................................13(e) Sand fill .................................................................................................................13

(f) Structural steel .......................................................................................................13

(g) Permanent Pile Casings .........................................................................................13

(h) Driven Pile Casings ...............................................................................................13

(i) Sheet Piles .............................................................................................................13

(j) Grouting.................................................................................................................14

8103 General............................................................................................................................14

(a) Subsurface Data.....................................................................................................14

(b) Channel preservation .............................................................................................14

8104 Cofferdams, Artificial Islands And Dewatering.............................................................14

(a) General ..................................................................................................................14

(b) Access....................................................................................................................15

(c) Dewatering ............................................................................................................15

8105 Excavation ......................................................................................................................15

(a) General ..................................................................................................................15

(b) Ground surface for excavation ..............................................................................16

(c) Excavation .............................................................................................................16

(d) Classification of excavated material......................................................................16

(e) Blasting..................................................................................................................17

(f) Deterioration of foundation excavations ...............................................................17

(g) Excavation safety...................................................................................................17(h) Inspection ..............................................................................................................17

(i) Excavation by hand ...............................................................................................17

8106 Foundation......................................................................................................................17

8107 Utilization Of Excavated Material..................................................................................18

8108 Backfill And Fill Near Structures...................................................................................18

(a) General ..................................................................................................................18

(b) Backfill ..................................................................................................................19

(c) Fill..........................................................................................................................19

(d) Select Granular Backfill ........................................................................................19

(e) Fill within restricted areas .....................................................................................20

8109 Foundation Fill ...............................................................................................................208110 Grouting Of Rock Fissures .............................................................................................21

8111 Foundation Dowels.........................................................................................................21


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Series 8000: Structures Standard Technical Specification -2002

Content

Page8000-2 Ethiopian Roads Authority

8112 Foundation Lining.......................................................................................................... 21

8113 Foundation Piling........................................................................................................... 21

(a) General.................................................................................................................. 21

(b) Piling Layout......................................................................................................... 21

(c) Alternative Designs for Piling and Piling Layouts ............................................... 22

(d) Details to be furnished by the Contractor ............................................................. 24(e) Pile-installation Frames and Equipment ............................................................... 24

(f) Piling Platforms..................................................................................................... 24

(g) Setting Out ............................................................................................................ 24

(h) Ground Surface of Foundation Piling ................................................................... 25

(i) Cast in situ concrete piles...................................................................................... 25

(j) Precast Concrete Piles........................................................................................... 26

(k) Steel Piles.............................................................................................................. 27

(l) Driving Piles ........................................................................................................ 27

(m) Augering and Boring............................................................................................. 29

(n) Rock Sockets......................................................................................................... 30

(o) Obstructions .......................................................................................................... 30(p) Determining Pile Lengths ..................................................................................... 31

(q) Piling Data............................................................................................................. 31

(r) Stripping the Pile Heads........................................................................................ 32

(s) Construction of Pile-capping Slab ........................................................................ 32

(t) Core Drilling ......................................................................................................... 32

(u) Load Test............................................................................................................... 33

(v) Defective Piles ...................................................................................................... 34

(w) Standing Time in Respect of Piles-installation Frames ........................................ 34

8114 Caissons ......................................................................................................................... 34

(a) General.................................................................................................................. 34

(b) Construction and sinking ...................................................................................... 34(c) Founding ............................................................................................................... 35

(d) Data ....................................................................................................................... 36

(e) Filling the caissons................................................................................................ 36

(f) Stripping................................................................................................................ 37

(g) Concrete screed below the caisson cover slabs..................................................... 37

8115 Measurement And Payment........................................................................................... 37

Item 81.01 Additional foundation investigations Provisional Sum .............................. 37

Item 81.02 Excavation of materials............................................................................... 37

Item 81.03 Access lump sum ........................................................................................ 38

Item 81.04 Drainage Lump Sum ................................................................................... 38

Item 81.05 Backfill to excavations utilizing ................................................................. 38

Item 81.06 Fill within restricted areas........................................................................... 39

Item 81.07 Overhaul in excess of 1.0 km, on excavated Material and on material

imported for backfill, foundation fill and fill for caissons.................................... 39

Item 81.08 Over break in excavation in hard material .................................................. 39

Item 81.09 Foundation fill............................................................................................. 39

Item 81.10 Establishment on site for the grouting of rock fissures............................... 40

Item 81.11 Move to and set up equipment at each hole to be drilled............................ 40

Item 81.12 Drilling of holes .......................................................................................... 40

Item 81.13 Grouting of holes ........................................................................................ 40

Item 81.14 Doweling into rock...................................................................................... 40Item 81.15 Foundation lining ........................................................................................ 40

Item 81.16 Establishment on the site for piling............................................................. 41


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Content


Item 81.17 Moving to, and setting up the equipment at each position for installing the

piles........................................................................................................................41

Item 81.18 Augered or bored holes for piles .................................................................41

Item 81.19 Driving the temporary casing for driven displacement piling systems for

forming holes for piles...........................................................................................42

Item 81.20 Manufacturing, supplying and delivering prefabricated piles .....................42Item 81.21 Installation of prefabricated piles ................................................................42

Item 81.22 Extra over item 81.18, irrespective of the depth, to form augered and bored

pile holes through identified obstructions .............................................................43

Item 81.23 Forming augered and bored pile holes through unidentified obstructions ..43

Item 81.24 Driving temporary casings for driven displacement piling systems or

installing prefabricated piles through identified or unidentified obstructions.......43

Item 81.25 Extra over items 81.18, 81.19 and 81.21 for raking piles............................43

Item 81.26 Forming under reams for piles.....................................................................43Item 81.27 Forming the bulbous bases for piles............................................................44

Item 81.28 Socketing piles into rock formation ............................................................44

Item 81.29 Installing and removing temporary casings in augered holes for piles .......44Item 81.30 Installing permanent pile casing for piles...................................................44

Item 81.31 Steel reinforcement in cast in situ piles:......................................................44

Item 81.32 Cast in situ concrete in piles, under reams, bulbous bases and sockets ......44

Item 81.33 Extra over item 81.32 for concrete cast under water...................................45

Item 81.34 Splicing/coupling prefabricated piles for lengthening.................................45

Item 81.35 Stripping/cutting the pile heads ..................................................................45

Item 81.36 Establishment on the site of the load testing of piles ..................................45

Item 81.37 Load tests on piles .......................................................................................45

Item 81.38 Establishment on the site for core drilling...................................................45

Item 81.39 Moving the equipment to and assembling it at each location where cores are

to be drilled............................................................................................................45Item 81.40 Drilling the cores .........................................................................................46

Item 81.41 Standing time for pile-installation frame.....................................................46

Item 81.42 Establishment on the site for constructing the caisson................................46

Item 81.43 Formwork for caissons ................................................................................46

Item 81.44 Steel reinforcement for caissons..................................................................46

Item 81.45 Cast in situ concrete in caissons and concrete seals ....................................47Item 81.46 Cutting edge for caissons.............................................................................47

Item 81.47 Sinking caissons through material situated .................................................47

Item 81.48 Excavation for caissons ...............................................................................47

Item 81.49 Filling the caissons ......................................................................................48

Item 81.50 Stripping the caisson heads. ........................................................................48

Item 81.51 Nuclear integrity testing on bored piles:......................................................48

DIVISION 8200 FALSEWORK, FORMWORK, AND CONCRETE FINISHES.................................49

8201 Scope ..............................................................................................................................49

8202 Dimensions .....................................................................................................................49

8203 Material Requirements For Falsework And Formwork .................................................49

(a) Falsework ..............................................................................................................49

(b) Formwork ..............................................................................................................49

8204 Design And Construction Requirements ........................................................................51

(a) Drawings................................................................................................................51

(b) Design....................................................................................................................52

(c) Construction ..........................................................................................................53


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Content


(d) Removal of forms and falsework .......................................................................... 57

8205 Formed Surfaces: Classes Of Finish .............................................................................. 59

(a) General.................................................................................................................. 59

(b) Class F1 surface finish .......................................................................................... 59

(c) Class F2 surface finish .......................................................................................... 59

(d) Class F3 surface finish .......................................................................................... 59(e) Board surface finish .............................................................................................. 59

(f) Protecting the surfaces .......................................................................................... 59

8206 Remedial Treatment Of Formed Surfaces ..................................................................... 60

(a) General.................................................................................................................. 60

(b) Repairs to surface defects ..................................................................................... 60

(c) Rubbing the surfaces............................................................................................. 60

8207 Unformed Surfaces: Classes Of Finish .......................................................................... 61

(a) Class U1 surface finish (rough) ............................................................................ 61

(b) Class U2 surface finish (floated)........................................................................... 61

(c) Class U3 surface finish (smoothly finished)......................................................... 61

8208 Measurement And Payment........................................................................................... 61Item 82.01 Formwork for indicated class of finish ....................................................... 61Item 82.02 Vertical formwork for indicated class of finish .......................................... 61

Item 82.03 Horizontal formwork for indicated class of finish ...................................... 61

Item 82.04 Inclined formwork for indicated class of finish .......................................... 62

Item 82.05 Permanent formwork................................................................................... 62

Item 82.06 Formwork to form open joints .................................................................... 62

Item 82.07 Establishment on the site for sliding formwork operations ........................ 62

Item 82.08 Transporting to and setting up the sliding formwork assembly.................. 63

Item 82.09 Forming the concrete by sliding formwork for structures .......................... 63

DIVISION 8300: STEEL REINFORCEMENT FOR STRUCTURES ............................................... 64

8301 Scope.............................................................................................................................. 64

8302 Materials Requirement................................................................................................... 64

(a) Steel reinforcement ............................................................................................... 64

(b) Mechanical couplers ............................................................................................. 64(c) Storage of Materials .............................................................................................. 64

8303 Construction Requirements............................................................................................ 64

(a) Equipment ............................................................................................................. 64

(b) Bending of Reinforcement .................................................................................... 65

(c) Surface Conditions................................................................................................ 65

(d) Placing and Fixing ................................................................................................ 65(e) Cover..................................................................................................................... 66

(f) Laps and Joints...................................................................................................... 67

(g) Welding................................................................................................................. 67

8304 Measurement And Payment........................................................................................... 68

Item 83.01 Steel reinforcement for structure................................................................. 68

Item 83.02 Mechanical couplers for.............................................................................. 68Item 83.03 Spacer "ladders".......................................................................................... 68

DIVISION 8400: CONCRETE FOR STRUCTURES ..................................................................... 69

8401 Scope.............................................................................................................................. 698402 Materials......................................................................................................................... 69

(a) Cement .................................................................................................................. 69


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Content


(b) Admixtures ............................................................................................................69

(c) Aggregates.............................................................................................................69

(d) Water .....................................................................................................................71

8403 Storage Of Materials.......................................................................................................72

(a) Cement...................................................................................................................72

(b) Aggregates.............................................................................................................72(c) Storage Capacity....................................................................................................72

(d) Deteriorated Material.............................................................................................72

8404 Concrete For Structures ..................................................................................................73

(a) Concrete Grade and Class .....................................................................................73

(b) Minimum Cement Content ....................................................................................73

(c) Maximum Water/Cement Ratio ............................................................................73

(d) Maximum Cement Content ...................................................................................73

(e) Design of Concrete Mixes for Structures ..............................................................73

(f) Prescribed mix .......................................................................................................74

8405 Construction Requirements ............................................................................................75

(a) Storage and Handling of Material .........................................................................75(b) Measuring Material. ..............................................................................................76

(c) Batching Plant, Mixers, and Agitators...................................................................76

(d) Mixing ...................................................................................................................77

(e) Delivery .................................................................................................................77

(f) Batching and Mixing .............................................................................................78

(g) Trial Mixes ............................................................................................................80

(h) Consistency and Workability.................................................................................80

(i) Temperature and Weather Conditions...................................................................80

8406 Handling, Placing And Compaction Of Concrete ..........................................................82

(a) General ..................................................................................................................82

(b) Placing ...................................................................................................................838407 Construction Joints .........................................................................................................87

(a) General ..................................................................................................................87

(b) Preparation of Surfaces..........................................................................................87

(c) Placing Fresh Concrete at Construction Joints ......................................................87

(d) Bonding .................................................................................................................88

(e) Bonding and Doweling to Existing Structures ......................................................88

8408 Expansion And Contraction Joints .................................................................................89

(a) Open joints.............................................................................................................89

(b) Filled joints ............................................................................................................89

(c) Steel joints .............................................................................................................89

(d) Water stops ............................................................................................................89(e) Compression joint seals.........................................................................................89

(f) Elastomeric expansion joint seal ...........................................................................90

8409 Finishing Plastic Concrete..............................................................................................90

(a) General ..................................................................................................................90

(b) Striking of Formwork ............................................................................................90

8410 Curing Concrete..............................................................................................................90

(a) General ..................................................................................................................90

(b) Forms inplace method ...........................................................................................91

(c) Water method ........................................................................................................91

(d) Liquid membrane curing compound method.........................................................91(e) Steam curing (precast units) ..................................................................................92

8411 Pipes And Conduits ........................................................................................................92


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(f) Positioning of Tendons and Duct Formers for Pre-stressing Tendons................105

(g) Tendon spacers ....................................................................................................105

(h) Grout....................................................................................................................105

(i) Protecting agents for unbonded tendons..............................................................106

(j) Testing .................................................................................................................106

8603 Construction Requirements ..........................................................................................106(a) Equipment............................................................................................................106

(b) Technical Data.....................................................................................................108

(c) Prestressing System .............................................................................................109

(d) Drawings Prepared By the Contractor.................................................................109

(e) Precasting ............................................................................................................110

(f) Pre-Tensioning ....................................................................................................111

(g) Post-Tensioning...................................................................................................111

8604 Loss Of Prestress ..........................................................................................................118

8605 Measurement And Payment..........................................................................................118

Item 86.01 Prestressing tendons ..................................................................................118

Item 86.02 Anchorages and couplers...........................................................................118Item 86.03 Extra over pay item 86.02 for partially tensioning the tendons ................119

DIVISION 8700 BRIDGE BEARINGS ...................................................................................120

8701 Scope ............................................................................................................................120

8702 Bridge Bearings ............................................................................................................120

(a) Material................................................................................................................120

(b) Concrete Hinges ..................................................................................................121

(c) Roofing Felt.........................................................................................................122

(d) Elastomeric Bearings...........................................................................................122

(e) Proprietary Bearings............................................................................................123(f) Dowels and Guides..............................................................................................126

(g) Storage and Handling ..........................................................................................126

(h) Installation ...........................................................................................................1268703 Bridge Parapets, Railings And Sidewalks ....................................................................127

(a) Materials ..............................................................................................................127

(b) Concrete Parapets ................................................................................................127

(c) Metal Railings .....................................................................................................128

(d) Bridge Number Plates..........................................................................................128

(e) Concrete Sidewalks .............................................................................................128

(f) Concrete Surface Finish Requirements ...............................................................129

(g) Construction Tolerances......................................................................................1298704 Joints In Structures .......................................................................................................129

(a) General ................................................................................................................129

(b) Movement joints ..................................................................................................129

(c) Materials ..............................................................................................................130

(d) Filled and unfilled joints......................................................................................132

(e) Epoxy Mortar Nosings ........................................................................................132

(f) Concrete Nosings.................................................................................................132

(g) Plug type expansion joint systems.......................................................................133

(h) Sealing Of Joints..................................................................................................133

(i) Proprietary Expansion Joints ...............................................................................135

(j) Installation Of Expansion Joints..........................................................................135

8705 No-Fines Concrete........................................................................................................136

(a) Materials ..............................................................................................................136


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(b) Grades on No-Fines Concrete ............................................................................. 136

(c) Batching and Mixing........................................................................................... 136

(d) Placing................................................................................................................. 137

(e) Protection ............................................................................................................ 137

8706 Drainage for Structures ................................................................................................ 137

(a) Weep holes, drainage pipes and channelling ...................................................... 137(b) No-fines concrete blocks..................................................................................... 137

(c) Synthetic-fibre filter fabric.................................................................................. 137

(d) Crushed stone in drainage strips behind walls .................................................... 138

8707 Measurement And Payment......................................................................................... 138

Item 87.01 Proprietary bearings .................................................................................. 138

Item 87.02 Installing the proprietary bearings ........................................................... 138

Item 87.03 Bearings .................................................................................................... 138

Item 87.04 Concrete hinges ......................................................................................... 138

Item 87.05 Bearing strips ............................................................................................ 139

Item 87.06 Dowels/guides........................................................................................... 139

Item 87.07 Concrete parapets ...................................................................................... 139Item 87.08 Steel railings.............................................................................................. 139

Item 87.09 End blocks................................................................................................. 139

Item 87.10 Numbers for structures.............................................................................. 139

Item 87.11 Proprietary expansion joints...................................................................... 140

Item 87.12 Installation of proprietary expansion joints .............................................. 140

Item 87.13 Expansion joints........................................................................................ 140

Item 87.14 Filled joints: .............................................................................................. 140

Item 87.15 Unfilled joints ........................................................................................... 141

Item 87.16 Sealing joints............................................................................................. 141

Item 87.17 Cast in situ no- fines concrete................................................................... 141

Item 87.18 Precast no-fines concrete units.................................................................. 141Item 87.19 Drainage pipes and weep holes................................................................. 141

Item 87. 20 Drainage gulleys ...................................................................................... 142

Item 87. 21 Synthetic-fiber filter fabric....................................................................... 142

Item 87. 22 Concrete channeling................................................................................. 142

Item 87. 23 Crushed stone in drainage strips .............................................................. 142

Item 87. 24 Nose endings at balustrades ..................................................................... 142

Item 87.25 Concrete transition blocks......................................................................... 142

DIVISION 8800:STRUCTURAL STEELWORK ......................................................................... 144

8801 scope............................................................................................................................. 1448802 Materials....................................................................................................................... 144

(a) Structural steel..................................................................................................... 144

(b) Bolts, nuts and washers....................................................................................... 144

(c) Friction-grip fasteners ......................................................................................... 144

(d) Welding consumables ......................................................................................... 144

(e) Test certificates ................................................................................................... 144

8803 Codes Of Practice......................................................................................................... 145

8804 Shop Details ................................................................................................................. 145

8805 Fabrication And Assembly........................................................................................... 145

(a) General................................................................................................................ 145

(b) Marking the steel................................................................................................. 145

(c) Cutting................................................................................................................. 145

(d) Holes for fasteners .............................................................................................. 145


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(e) Joints in compression ..........................................................................................145

(f) Hollow sections ...................................................................................................145

(g) Alignment of holes ..............................................................................................146

(h) Welding ...............................................................................................................146

(i) Bolting .................................................................................................................146

(j) Welded Stud Shear Connectors ...........................................................................146(k) Friction-grip fastening .........................................................................................146

(l) Riveting ...............................................................................................................147

(m) Trimming .............................................................................................................147

(n) Corrosion prevention ...........................................................................................147

8806 Erection.........................................................................................................................147

(a) General ................................................................................................................147

(b) Safety during erection..........................................................................................148

(c) Alignment ............................................................................................................148

(d) Corrections ..........................................................................................................148

(e) Grouting...............................................................................................................148

8807 Testing ..........................................................................................................................149(a) Testing by the engineer .......................................................................................149

(b) Process control.....................................................................................................149


Item 88.01 Structural steel ...........................................................................................149

Item 88.02 Anchor bolts ..............................................................................................150

Item 88.03 Corrosion protection ..................................................................................150

DIVISION 8900: STONE MASONRY STRUCTURES .................................................................151

8901 scope .............................................................................................................................151

8902 Stone Masonry Walls ...................................................................................................1518903 Classes Of Masonry......................................................................................................151

8904 Material Requirements For Stone Masonry Structures ................................................152

(a) Stone ....................................................................................................................152

(b) Quarry Operations ...............................................................................................154

(c) Mortar ..................................................................................................................1548905 Construction Requirements ..........................................................................................154

(a) Excavation and backfill .......................................................................................154

(b) Falsework ............................................................................................................155

(c) Selection and Placing ..........................................................................................155

(d) Beds and Joints ....................................................................................................156

(e) Headers ................................................................................................................157(f) Backing................................................................................................................157

(g) Coping .................................................................................................................157

(h) Parapet walls........................................................................................................157

(i) Facing for Concrete .............................................................................................157

(j) Pointing................................................................................................................158

(k) Weep Holes .........................................................................................................159

(l) Cleaning Exposed Faces......................................................................................159

(m) Weather Limitations ............................................................................................159


Item 89.01 Stone masonry walls..................................................................................159


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DIVISION T8000: CONSTRUCTION TOLERANCES FOR STRUCTURES.................................. 161

T8001 Scope...................................................................................................................... 161

T8002 Definitions.............................................................................................................. 161

T8003 Tolerances .............................................................................................................. 161

(a) Foundations......................................................................................................... 162

(b) Footings, pile capping slabs, caisson cover slabs, etc......................................... 163(c) Columns, walls, pier, abutments, etc .................................................................. 163

(d) Bridge And Culvert Superstructure..................................................................... 164

(e) Precast Beams ..................................................................................................... 164

(f) Precast Beams And Panels.................................................................................. 165

(g) Precast Prestressed Concrete Structural Elements .............................................. 166

(h) Reinforcing Steel................................................................................................. 167

(i) Prestressing ......................................................................................................... 168

(j) Bridge Bearings................................................................................................... 168

(k) Fabrication And Assembly Tolerances For Structural Steel............................... 169

(l) Concrete Pavement Slab ..................................................................................... 169

(m) Miscellaneous...................................................................................................... 172


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List of Tables and Figures


LIST OF TABLES AND FIGURES

Table 8102-1: Rock Classification ..........................................................................................12

Table 8108-1 Select Granular Backfill Gradation...................................................................20

Table 8204-1 Minimum Form/Support Release Criteria.........................................................58

Table 8303-1 Minimum concrete cover over reinforcement...................................................67

Table 8304-1 Mass of Reinforcing Bars .................................................................................68

Table 8402-1 Maximum amount of deleterious substances ....................................................70

Table 8402-2 Grading of Fine Aggregate................................................................................71

Table 8402-3 Nominal Size and Grading of Coarse Aggregate..............................................71

Table 8404-1 Grade of Concrete for Structures ......................................................................73

Table 8404-2 Nominal Mixes..................................................................................................75Table 8406-1 Hand Held Vibratory Requirements..................................................................87

Table 8409-1 Minimum Period Before Striking Formwork for Concrete for Structures........90

Table 8700-2 Types of movement joints...............................................................................129

Table 8700-1 Grades of No-Fines concrete...........................................................................136


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Division 8100: Foundations For Structures


DIVISION 8100: FOUNDATIONS FOR STRUCTURES

8101 SCOPE

This Division provides specifications for the construction of foundations for structuresincluding bridges, retaining walls, box and slab culverts etc. It provides in particular

specifications for excavation, and back filling and for the construction of the foundation it self

as well as the pile capping slabs or the caisson cover slabs.

8102 MATERIALS

(a) General

Materials used in the permanent foundation work shall comply with the requirements

specified for the particular material in series 8000 of the Specifications.

(b) Rock (for rock fill)

Stones shall be hard, angular, field or quarry stones of such quality that they will not

disintegrate on exposure to water or weathering.

The stones shall be free from overburden, shale, and organic material.

Neither the breadth nor thickness of a single stone shall be less than one-third its length.

Not more than 10% of the total volume of rock fill shall consist of stones having a mass of

less than 0.5 of the mass specified and not more than 10% of the total volume of rock fill shall

consist of stones having a mass more than 5 times the mass specified. Not less than 50% ofthe total volume of rock fill shall consist of stones larger than the specified mass.

Table 8102-1: Rock Classification

Class Description Description of HardnessField Indicator Tests

Unconfined

Compressive

Strength

(MPa)

R1 Very soft

rock

Material crumbles under firm (moderate) blows with a

sharp end of geological pick and can be peeled offwith a knife; it is too hard to cut a tri-axial sample by

hand

0.7 to 3.0

R2 Soft rock Can just be scraped and peeled with a knife;

indentations 1 mm to 3 mm show in specimens with

firm (moderate) blows of the pick point

3.0 to 10.0

R3 Hard rock Cannot be scraped or peeled with a knife; handheld

specimen can be broken with hammer end of a

geological pick with a single firm (moderate) blow

10.0 to

20.0

R4 Very hard

rock

Hand-held specimen Breaks with hammer end of pick

under more than one below

20.0 to

70.0

R5 Extremely

hard rock

Specimen requires many blows with geological pick

to break through intact material

More than

70.0


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(c) Crushed stone

Crushed stone used for the construction of crushed stone fill shall be from sound unweathered

rock approved by the Engineer.

(d) Granular fillGranular fill used for the construction of compacted granular fill shall be approved granular

material of at least gravel sub-base quality.

Granular back fill required for compacting against earth-retaining structures shall consist of

well-graded crushed or uncrushed gravel, stone, rock fill, or natural sand or a combination of

any of these. It shall not contain a soluble sulphate content exceeding 2.5 g per liter as

determined in accordance with the requirements of AASHTO.

Not less than 95 per cent of the material shall pass a 125mm BS sieve and at least 90 per cent

shall pass the 75mm BS sieve but not more than 10 per cent shall pass the 75-micron BS

sieve.

(e) Sand fill

Sand used for filling of caissons shall be clean, hard and free from lumps of clay, organic or

other deleterious matter.

(f) Structural steel

Steel in steel piles shall comply with the requirements of BS 4360 and/or AASHTO M 183 for

the grade of steel specified on the Drawings.

I and H sections shall comply with the requirements of BS 4: Part 1.

Fabricated sections shall comply with the details shown on the Drawings.

(g) Permanent Pile Casings

Permanent piles casings shall be sufficiently rigid so as not to deform permanently or damage

during handing and construction.

The casings shall be sufficiently dense to prevent the fluid components of the concrete from

leaking during the placing of the concrete or thereafter.

Where steel casings contribute to the strength of the pile, the casings shall have a minimum

wall thickness of 4.5 mm and shall comply with the requirements of ASTM A 252-68. Weldedjoints shall comply with the requirements of Division 8800 of these specifications.

(h) Driven Pile Casings

Driven pile casings shall have sufficient strength to permit their being driven and not being

distorted by the driving of adjacent piles, and they shall be sufficiently watertight to prevent

water leaking through the casing walls during the placing of concrete.

(i) Sheet Piles

For steel sheet piles, conform to AASHTO M 202M or M 223M.

For all other sheet piles, conform to the requirements prescribed above for the particular

material specified. Make the joints practically watertight when the piles are in place.


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(j) Grouting

(i) Cement grout

Cement grout shall meet the appropriate requirements of sub-clause 8602(h) of these

specifications.

(ii) Proprietary-brand grout

Proprietary brand grout shall be prepared and used strictly in accordance with the instructions

of the manufacturer.

8103 GENERAL

(a) Subsurface Data

If it is found during the course of excavation that the load bearing strata differs from that

shown on the Drawings, the Contractor shall immediately notify the Engineer.

The Engineer shall be entitled, as often as he may deem necessary during the course of

excavation, to call upon the Contractor to perform additional foundation investigation and/or

tests at or below the respective foundation levels to establish safe bearing pressures and

foundation depths.

(b) Channel preservation

Stream flow and preservation of marine and freshwater life shall be maintained at all times.

Access to cofferdams, artificial islands and piling platforms shall be accomplished without

disrupting the stream flow at the point of crossing unless otherwise specified in the SpecialProvisions.

On completion of the work surplus excavated materials, including materials excavated from

caisson compartments and piles, materials used in cofferdams and other temporary works, as

well as in-situ material, shall be removed and disposed of by the Contractor to the original bed

level or such lower elevation as agreed to by the Engineer or required for stream

channelization works.

8104 COFFERDAMS, ARTIFICIAL ISLANDS AND DEWATERING

(a) General

This clause covers the provision of access, including the construction of cofferdams, and

draining the excavations.

Where it is unnecessary to provide access in terms of sub-clause 8104(b), the contractor shall

be paid separately for draining the excavations.

After Completion of the permanent works, all temporary works shall be completely removed,

the ground leveled and the site left neat. Where this is impracticable, such portions as have

not been removed, shall be dealt with in accordance with the engineers instructions.


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(b) Access

Where temporary banks or artificial islands are constructed in view of affording access to the

location where structural members, piles or caissons are to be constructed, the banks or

islands shall be adequately compacted in view of supporting any plant and material without

any undue settling, which may have a harmful effect on the end product.

The contractor may use any material deemed by him to be suitable for constructing the

islands, but he shall note that no separate payment will be made in terms of items 81.02(b),

81.22, 81.24 and 81.48(b) for any obstructions or hard materials occurring in the material

used for constructing temporary banks or artificial islands.

Designing and constructing any cofferdams shall comply with the requirements of BS 8004.

Before starting with construction, the contractor shall submit drawings to the engineer, which

show details of the cofferdams and the method of construction.

(c) Dewatering

The Contractor shall be responsible for preventing the ingress of water into excavations.

The preventative measures shall include the construction of proper drainage channels,

diversion channels, sumps, the supply and operation of the necessary bailing and pumping

equipment and the construction of suitable watertight cofferdams.

The dewatering measures, with the exception of pumping, shall be maintained until the

backfilling has been completed.

Between the various construction stages pumping may be interrupted as agreed by the

Engineer. Any draining or pumping of water from cofferdams or the interior of any foundation

enclosure shall be done in such a manner as to preclude the possibility of any portion of the

concrete materials being carried away.

8105 EXCAVATION

(a) General

This work shall include excavations, not provided for elsewhere in these Specifications,

required for the foundation of structures as well as for the excavating required for existing

bridges and culverts where these have to be demolished, extended or modified.

Excavation required for diverting, channeling or widening streams within 5.0 m of concrete

structures shall be measured and paid for under item 81.02. Excavations beyond the 5.0 mlimit shall be measured and paid for under the appropriate items of series 3000 and 4000 of

these specifications.

The Engineer may require additional excavation, to that described in the Contract, to remove

any pockets of soft soil or loose rock and the resulting voids and any natural voids shall be

filled with Grade 20/20 concrete complying with the requirements of clause 8404 of these

specifications or other material as instructed by the Engineer.

No trimming of the sides of the excavation shall be carried out within 24 hours of the placing

of any blinding concrete.

Any additional excavation below the bottom of foundations, including that resulting from

removal of material which the Contractor has allowed to deteriorate shall be replaced with

Grade 20/20 concrete complying with the requirements of Division 8400 A of these

specifications or other material as instructed by the Engineer.


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The sides of the excavation for foundations for structures shall either be vertically or sloped at

a safe angle for the material to be excavated. Except in rock, vertical sides shall be adequately

supported at all times to the satisfaction of the Engineer.

All practical measures shall be taken to prevent the ingress of surface water into the excavated

foundations. Any water collecting in the excavated foundation shall be removed as soon as

possible thereafter.

(b) Ground surface for excavation

Prior to commencement of any excavation, the Contractor shall notify the Engineer in good

time to ensure that measurements, cross sections and levels of the undisturbed ground can be

taken in order that an average ground surface from which the excavation is to be measured

can be established and agreed upon between the Engineer and the Contractor.

(c) Excavation

Where, in the opinion of the Engineer, the casting of concrete against the excavated earthfaces is not permissible, or where formwork has to be provided, the extremities of the

excavation, for purposes of measurement and payment, shall be deemed to be the vertical

planes parallel to and 0.6 m outside the perimeter of the member for which formwork is to be

provided.

Where suitable stable material is encountered during excavation, that part of the trench or

foundation pit shall be excavated to the neat dimensions of the base unless directed otherwise

by the Engineer.

Over excavation (over break) in hard material shall be backfield with the same class of

concrete as that in the base or with mass concrete fill as specified or as directed by the

Engineer.

Where blasting is required, the contractor shall complete the entire foundation excavation

before he commences with the construction of any permanent concrete work, unless otherwise

approved by the Engineer.

Boulders, logs, or any other unsuitable material excavated shall be spoiled.

When hard material suitable for foundation is encountered at the foundation level, it shall be

cut and trimmed to a firm surface, either level, stepped or serrated, as required.

Where the material at the foundation level is soft material or hard material that deteriorates

rapidly on exposure, excavation to final grade and elevation shall not be made until just

before the blinding layer is placed.

Where, in the opinion of the Engineer, unsuitable material is encountered at foundation level,

such material shall be removed and replaced with foundation fill in accordance with Clause

8109 and as directed by the Engineer.

(d) Classification of excavated material

Distinction shall be made for payment purposes between excavation in hard and soft material.

All excavation for the foundations of structures shall be classified in accordance with the

following classifications:


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(i) Hard material

Material, which cannot be excavated except by drilling and blasting, or the use of pneumatic

tools or mechanical breakers shall be classified as hard material.

(ii) Soft material

All material not classified as hard material shall be classified as soft material.

(e) Blasting

Where blasting is permitted it shall be carried out in accordance with the requirements of the

Contract.

(f) Deterioration of foundation excavations

Where the bottoms or sides of excavations, in which bases are to be cast, are softened due to

negligence on the part of the Contractor in allowing storm or other water to enter the

excavations, the softened material shall be removed and replaced with foundation fill asdirected by the Engineer at the Contractor's expense.

(g) Excavation safety

The Contractor shall take the necessary precautions to safeguard the stability and safety of the

excavations and adjacent structures.

The personal safety of any person shall not be placed in jeopardy nor shall any situation be

allowed to arise which may result in damage of whatsoever nature.

(h) Inspection

No concrete shall be placed before the excavation has been properly cleaned and inspected

and approved by the Engineer.

(i) Excavation by hand

Where circumstances prevent the use of mechanical excavators and material can be removed

only by hand implements, the Engineer shall authorise the supplementary payment to the

contractor for such work at the tendered rates for excavation by hand should he be satisfied

that the contractor had been unable to prevent the necessity for excavation by hand by proper

planning and precautionary measures.

The supplementary rate for excavation by hand shall not apply to minor finishing or clearing

jobs in excavations which are otherwise being done by mass excavation plant.

8106 FOUNDATION

In consequence of possible variations of anticipated foundation conditions the dimensions and

foundation levels specified or shown on the Drawings may have to be varied during

construction.

The Engineer has the full and absolute power in terms of this contract to order such variations

and to specify the actual foundation level for each foundation fill, base, or caisson duringconstruction and his decision shall be final and binding on the Contractor.


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The Contractor shall not be entitled to any additional payment in consequence of any such

variation in the dimensions or foundation depths over and above that provided for in Clause

8115 regardless of the stage of construction at which the instruction to vary the dimensions or

foundation depths is given. However, if in consequence of such variation order the Contractor

is compelled to substitute machines and equipment with other machines and equipment in

order to successfully complete the work, the Engineer may, at his discretion, reimburse theContractor for additional expenses incurred provided that the original machines and

equipment were suited to the work required prior to the variation order being issued.

No base, caisson, or pile shall be founded unless authorized by the Engineer. Each foundation

level shall be accurately measured and recorded.

The term foundation level used in these Specifications shall be deemed to have the

following meanings in respect of:

(i) Foundation fill : The surface of the in-situ material that has been prepared to receive

foundation fills.

(ii) Bases : The underside of the base.(iii) Piles : The underside of the under ream, bulbous base or rock socket; the tip of the pile

shoe or lower pile end, as may be relevant.

8107 UTILIZATION OF EXCAVATED MATERIAL

Excavated material and material recovered from temporary work shall, so far as it is suitable,

be utilized for backfill.

Material unsuitable for use as backfill or in excess of the quantity required to complete the

backfill shall be spoiled or utilized as directed by the Engineer.

Excavated material not used for backfill or not taken to spoil but used in the construction of

embankments or other parts of the work, as directed by the Engineer, will be paid for under

foundation excavation as well as under the relevant item for the purpose for which it is used.

The free-haul distance on excavated material and imported material for backfill shall be 1.0

km.

Excavated and stockpiled material shall be deposited so as not to endanger the uncompleted

structure, either by direct pressure or indirectly by overloading the banks contiguous to the

structure or in any other way.

8108 BACKFILL AND FILL NEAR STRUCTURES

(a) General

In placing backfill and fill, the following precautions shall be taken:

The material shall be placed simultaneously, in so far as is possible, to approximately the

same elevation on both sides of an abutment, pier, or wall where appropriate.

If conditions require placing backfill or fill appreciably higher on one side than on the

opposite, the additional material on the higher side shall not be placed until authorized by the

Engineer and preferably not until the concrete has been in place 14 days, or until tests show

that the concrete has attained sufficient strength to safely withstand any pressure created bythe backfill or fill, or the method of construction.


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The material behind abutments restrained at the top by the superstructure. e.g., portal type

structures, shall be placed as stated on the Drawings or as directed by the Engineer.

The material behind the walls of concrete culverts shall not be placed until the top slab is

placed and cured, unless authorized otherwise by the Engineer.

(b) Backfill

Excavated areas around structures shall be backfilled with approved material in horizontal

layers, not exceeding 150 mm in depth after compaction, to the level of the original ground

surfaces.

Each layer shall be moistened or dried to optimum moisture content for the material and

compacted to a density of not less than 93% of Modified AASHTO density.

(c) Fill

To prevent wedge action against the structure and bounding slopes, the slopes shall be

benched or serrated.

In no case shall the toe of the bounding fill be closer to the concrete face than the height of the

exposed face of the abutment or wall.

(d) Select Granular Backfill

Select granular backfill shall be sound, durable, granular material free from organic matter or

other deleterious material (such as shale or other soft particles with poor durability).

Select granular backfill shall conform to the following:

(i) Quality Requirements

(1) Gradation according to; Table 8108-1

(2) Shear angle of internal friction, AASHTO T 236 34o

min.

Note:

Samples shall be compacted as per AASHTO T 236 to 95 percent of the maximum density

determined according to AASHTO T99 method C or D and corrected for oversized

material according to AASHTO T 99, Note 7.

(3) Sodium sulfate soundness loss (5 cycles);15% max. according toAASHTO T 104.

(4) Los Angeles abrasion, according to AASHTO T96; 50% max.(5) Liquid limit, according to AASHTO T89; 30 max.

(ii) Electrochemical requirements

(1) Resistively, AASHTO T 226 3000 cm min.(2) pH, AASHTO T 289; 5.0 to 10.0

(3) Sulfate content, AASHTO T 290 1000 ppm max.

(4) Chloride content, AASHTO T 291 200 ppm max.

Note: Tests for sulfate and chloride content are not required when pH is between 6.0 and 8.0

and the receptivity is greater than 5000 ohm centimeters.


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Table 8108-1 Select Granular Backfill Gradation

Sieve Size Percent by Mass Passing Designated Sieve

(AASHTO T27 and T11)

100 mm 100

75 mm 75 10075 m 0 15

(e) Fill within restricted areas

The portion of the fill within 3 meters of the concrete faces of the structure and the whole of

the spill through portion, or the extent shown on the Drawings, shall be termed "fill within

restricted area".

Fill within the restricted area shall comply with the requirements of Series 4000 except that it

shall be compacted to a density of not less than 93% of Modified AASHTO density. In order

to achieve the specified density, the Contractor shall, where necessary, import material of

suitable quality.

Payment in accordance with Pay item 81.06 for the construction of fill within restricted areas

shall only be made when specifically provided for in the Bill of Quantities.

8109 FOUNDATION FILL

If it is found during the course of excavation that the material at the indicated foundation

depth does not have the required bearing capacity as specified on the Drawings, the

excavations shall be extended at the discretion of the Engineer until satisfactory foundation

material is encountered.

The Engineer reserves the right to order the Contractor to make up the difference in levels

with foundation fill.

Where the foundation fill consists of rock or crushed stone fill, it shall be constructed in

accordance with the requirements of the Special Provisions or as directed by the Engineer.

Foundation fill consisting of granular material shall be constructed in layers not exceeding

150 mm in thickness after compaction. Each layer shall be moistened or dried to optimum

moisture content for the material and compacted to a density of not less than 95% of Modified

AASHTO density.

Mass concrete fill to be used shall be of the class or mix as specified or directed by theEngineer.

Unless specified or directed otherwise by the Engineer, the minimum foundation fill

consisting of rock fill, crushed stone fill or compacted granular fill to be constructed shall be

defined by a prism with plan area coinciding with the lower base of a truncated pyramid the

sides of which slope at an angle of 60o

with the horizontal from the underside of the footing or

slab to the foundation level.

A concrete blinding of 75mm thickness and Grade 15/20 concrete shall be placed underneath

all bases except where mass concrete fill is used or where authorized by the Engineer.

Where mass concrete is constructed under a base it shall be constructed accurately to the finallevels of the underside of the base.


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8110 GROUTING OF ROCK FISSURES

Where specified, fissures in the rock below and around the base shall be sealed by pressure

grouting with a neat cement or sand-cement grout with a water cement ratio as agreed to by

the Engineer. The extent of fissuring shall be established by water testing under pressure.

Holes of at least 40 mm diameter shall be drilled in positions ordered by the Engineer andgrout pumped into these holes under suitable pressures.

Grouting shall be carried out in 3-meter stages to the maximum depth ordered. Care shall be

taken to avoid further fracturing of the rock strata due to excessive grouting pressures.

Grouting of rock fissures shall be carried out by specialized operators with adequate

experience in this class of work.

8111 FOUNDATION DOWELS

Where required, foundation dowels of the specified material, diameter and length shall be

installed at the positions and to the dimensions shown on the Drawings or as directed by theEngineer.

After exposure, clearing and trimming of the rock formation, holes of not less than 40 mm

diameter and of specified depth shall be drilled into the rock into which the dowels shall be

fox-wedged and grouted with a 2:1 sand: cement grout.

8112 FOUNDATION LINING

Where specified or directed by the Engineer, foundation lining shall be installed as described

hereinafter.

The Engineer shall have the right to order the use of lining against sides of excavations andunderside of bases and slabs in lieu of formwork and concrete building.

All surfaces to be lined shall be covered with approved sheeting to provide a clean impervious

layer. The material shall be of sufficient strength to provide a durable working surface and to

support the concrete and reinforcement without tearing.

The joints between strips shall have a 150 mm overlap and the lining shall be held firmly in

position by nails, pegs, etc.

Polyethylene sheeting of 0.15 mm thickness is generally considered adequate for the use

under approach (jockey) slabs and bases.

8113 FOUNDATION PILING

(a) General

This section covers the construction of bearing piles of concrete or steel or a combination of

these materials.

(b) Piling Layout

The piling layout, the minimum pile size and/or bearing capacity and type together with the

steel reinforcement and class of concrete required shall be as detailed and specified on thedrawing unless otherwise specified in the project specifications.


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(c) Alternative Designs for Piling and Piling Layouts

(i) Submission

The priced schedule of quantities submitted for alterative designs shall be complied strictly in

accordance with the relevant measurement and payment clauses of these specifications.

Where pay items defined in these specifications have been omitted, it shall mean either that

the items do not apply, or that where the engineer requires work falling under such items to be

done, it shall be done without any cost to the employer. The inclusion of "rate-only" items will

not be permitted.

Where pay items not defined in these specifications are used, the measurement and payment

requirements for such items shall be specified in detail by the contractor. In the absence of

such definitions, or in the case of any ambiguity, the interpretation of the engineer shall be

final and binding.

Except in piling-only contracts or where otherwise provided in the Project specifications, the

contractor shall price the schedule of quantities for the original design irrespective of whetheror not an alterative design is offered.

(ii) Design

The critical design-load combinations acting upon the underside and the center of gravity of

the pile-capping slab, the maximum permissible stet of the pile-capping slab, and the technical

data required for designing alternative piles and/or piling layouts will be indicated on the

drawings.

Alternative designs shall comply with the provisions of the Contract and the prescriptions set

out below.

For alternative designs submitted the contractor shall submit with his tender a detaileddescription of the method of analysis used in the design of the piles and the pile-group

layouts.

The average length of pile and/or of the piles per group on which the quantities in the

schedule of quantities for the alternative designs are based shall be stated in each case. The

type of pile offered shall be defined in terms of size, materials, working and breaking load.

The Contractor shall be responsible for and shall bear the cost for redesigning, drafting and

submitting the detail drawings for any structural element affected by the alternative pile

design. Any economy or incidental caused by constructing such element as compared to the

original design shall be for the account of the contractor.

The contractor shall, as specified in the Contract, submit to the Engineer at least three months

prior to work being commenced, drawings detailing the piling-group layout and piles,

incorporating such amendments to his original design as may be required by the engineer, and

drawings detailing the amendments required to the pile-capping slab dimensions and

reinforcement as a result of the layout of the piles, all as applicable.

No work of whatsoever nature shall be commenced on the piling until the drawings have been

submitted to and have been approved by the engineer, in writing.

After approval of the drawings, no departure there from shall be made with out authorization

by the Engineer.

Where the alternative piles fail in regard to the load test specified in sub-clause 8113(u) ofthese specifications, the contractor shall be responsible for the cost of the work required for

improving the piles and pile layout so as to comply with the design requirements.


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(iii) Basis of payment

Where the quantities in the schedule of quantities referred to in sub-clause 8113(c)(i), on the

one part, differ from the number of piles and the average pile length given in the submission

for the alternative pile design, on the other part, the Engineer shall accept the sum in the said

schedule of quantities, correct the quantities, and adjust the rates for the applicable pay items

accordingly.

In addition to these corrections, the employer shall be justified in using one of the following

methods for paying for piles constructed in accordance with the alternative design:

Method 1

The employer may check the alternative designs, calculate the quantities and adjust the rates

as set out in the first paragraph of sub-clause 8113(c)(iii). The employer will then pay for the

work in accordance with the actually measured quantities.

Method 2

The employer may use the following formulae for calculating the quantities under pay items81.17 to 81.35 for payment:

Np=Nd

Lp = Nd .Ld + Nb(Lb-Ld)K for Nd > Nb

and

Lp = Nd . Ld + Nd(Lb-Ld)K for Nd < Nb

Ld

LbK = for Ld > Lb and K =

Lb

Ldfor Ld Lb

Where: P = paid, d = designed and, b = built.

The term "units" means items of work measured and paid for in the respective pay items such

as piles, raking piles, casings, underreams, concrete, etc.

Np = number of "units" measured and finally paid for in a particular pile group.

Nd =number of "units" provided for in the tender for the alternative design in the same pile

group.

Nb = number of approved and accepted "units' finally installed in the same pile group.Lp = the length of the "units" measured and paid for or the length to be used in calculating

quantities which are a direct function of the length of the "units" for the same pile group.

Ld = the averag

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08-Series 8000 Structures