World Housing Encyclopedia Report

Country: Kyrgyzstan

Housing Type: Prefabricated concrete panel buildings with monolithic panel joints (seria105).

Contributors:Svetlana UranovaUlugbek T. Begaliev

Primary Reviewer:Svetlana Brzev

Created on: 6/5/2002Last Modified: 7/2/2003

This encyclopedia contains information contributed by various earthquake engineering professionalsaround the world. All opinions, findings, conclusions, and recommendations expressed herein are those

of the various participants, and do not necessarily reflect the views of the Earthquake EngineeringResearch Institute, the International Association for Earthquake Engineering, the Engineering Information

Foundation, John A. Martin & Associates, Inc. or the participants' organizations.

Table of Contents

General Information............................................................................................1Architectural Features........................................................................................ 3Socio-Economic Issues...................................................................................... 4Structural Features............................................................................................. 6Evaluation of Seismic Performance and Seismic Vulnerability.......................... 10Earthquake Damage Patterns............................................................................ 12Building Materials and Construction Process..................................................... 13Construction Economics.....................................................................................15Insurance............................................................................................................16Seismic Strengthening Technologies................................................................. 17References......................................................................................................... 18Contributors........................................................................................................ 19Figures................................................................................................................20

1 General Information

1.1 CountryKyrgyzstan

1.3 Housing TypePrefabricated concrete panel buildings withmonolithic panel joints (seria 105).

1.4 SummaryPrefabricated concrete panel buildingconstruction with monolithic panel joints hasbeen practiced throughout the former SovietUnion (including Kyrgyzstan) since 1965. Thistype of prefabricated construction is known asseria 105. Apartment buildings of this type areusually 5-9 stories high. The foundations aremade of cast in-situ reinforced concrete. Steeldowels are provided in the foundations to ensureanchorage of steel rebars located in the panelsand in the panel joints. The load-bearingstructure in large panel buildings consists ofreinforced concrete panels combined to form abox-type rigid system by means of special joints.This building type is considered to be one of themost earthquake-resistant construction types inthe former Soviet Union.

FIGURE 1A: Typical Building

1.5 Typical Period of Practice for Buildings of This Construction TypeHow long has thisconstruction been practiced< 25 years< 50 years X< 75 years< 100 years< 200 years> 200 years

Is this construction still being practiced? Yes NoX

1.6 Region(s) Where UsedIn most large cities of Kyrgyzstan and other republics of the former Soviet Union. In Kyrgyzstan, buildingsof this construction type can be found in the following cities: Bishkek, Tokmok, Och, Karakol (Kyrgyzstan).Large panel buildings account for up to 35% - 40% of the multi-story residential building stock in thecapitol, Bishkek. Buildings of this type are less common in other cities mentioned above.

1.7 Urban vs. Rural ConstructionWhere is this construction commonly found?In urban areas XIn rural areasIn suburban areasBoth in rural and urban areas

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Additional Comments: There are large panel buildings in suburban areas too.

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2 Architectural Features

2.1 OpeningsLarge panel prefabricated construction technology does not allow for a variation in the size of door andwindow openings. Usually, for a 3.6 m long panel, the window size is 1.82 m (width) X 1.53 m (height); fora 2.7 m long panel - the window size is 1.24 m (width) X 1.53 m (height). The size of a balcony door(together with window) is either 2.25 m or 1.66 m wide and 1.9 m in height. The overall window and doorarea account for 17% of the overall wall area. There are 16 windows for a building with plan dimensionsof 10.8 m X 25.2 m.

2.2 SitingYes No

Is this type of construction typically found on flat terrain? XIs this type of construction typically found on sloped terrain? (hilly areas) XIs it typical for buildings of this type to have common walls with adjacentbuildings?

X

The typical separation distance between buildings is 10 meters

2.3 Building ConfigurationThe typical shape of a building of this housing type is rectangular.

2.4 Building FunctionWhat is the main function for buildings of this type?Single family houseMultiple housing units XMixed use (commercial ground floor, residential above)Other (explain below)

2.5 Means of EscapeThere is one stair in each building unit (with average plan dimensions 10.8 m X 12.6 m).

2.6 Modification of BuildingsBuildings of this type are generally standardized and therefore modifications are not very common.Typical modifications include perforation of new door openings.

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3 Socio-Economic Issues

3.1 Patterns of OccupancyIn general, in a building of this type there are 4--8 housing units per building unit ("Block-Section"). Onefamily occupies one housing unit. Depending on the size of the building (number of stories), there are 20to 36 families occupying one building unit.

3.2 Number of Housing Units in a Building60 units in each building.

Additional Comments: The number of units can vary between 40-80.

3.3 Average Number of Inhabitants in a BuildingHow many inhabitants reside in a typical building of thisconstruction type?

During the day / businesshours

During the evening / night

< 55 to 1010-20> 20 X XOther

3.4 Number of Bathrooms or Latrines per Housing UnitNumber of Bathrooms: 1Number of Latrines: 1

Additional Comments: Very often bathroom and latrine are combined.

3.5 Economic Level of InhabitantsEconomic Status House Price/Annual Income

(Ratio)Very poor /Poor X /Middle Class X /Rich /

Additional Comments: 40% poor, 60% middle class

3.6 Typical Sources of FinancingWhat is the typical source of financing for buildings of this type?Owner FinancedPersonal Savings XInformal Network: friends and relativesSmall lending institutions/microfinance institutionsCommercial banks / mortagesInvestment poolsCombination (explain)Government-owned housing XOther X

3.7 Ownership

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Type of Ownership/OccupancyRentOwn outright XOwn with Debt (mortgage or other)Units owned individually (condominium) XOwned by group or poolLong-term leaseOther

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4 Structural Features

4.1 Lateral Load-Resisting SystemThe lLateral load-resisting system consists of large reinforced concrete panels acting as shear walls. Allwall and floor panels are combined together, thus creating a rigid structure by means of special jointsystem. Horizontal and vertical steel dowels are provided in wall and floor panels. Once the panels areerected in their final position, the dowels are welded, and the gaps between the panels are filled with castin-situ concrete. Shear stress in the joints is resisted by means of shear keys. Vertical steel bars areplaced close to the window and door openings in the panels. These bars are located in vertical joints.FIGURE 4A shows a typical precast floor panel with steel dowels and grooves (shear keys) for achievingmonolithic concrete panel joints. Details of a typical wall panel without openings are shown in FIGURE4B, whereas a typical panel with a wall opening is shown in FIGURE 4C. Horizontal and vertical sectionsof exterior wall panels are shown in FIGURE 4D and FIGURE 4E respectively. Horizontal and verticalsections of an interior panel are shown in FIGURE 4F and FIGURE 4G respectively. Wall and floor paneldimensions are of room size. Interior wall panels and floor panels are of normal-weight concrete (density24 kN/m³), and the facade (exterior)-wall panels are of light-weight concrete. The thickness of the interiorwall panels is typically 120 mm or 160 mm. The size of a typical wall panel is 2.7 m (width) X 3 m (height)or 3.6 m (width) X 3.0 m (height). The thickness of a floor panel is 160 mm.

4.2 Gravity Load-Bearing StructureThe gravity load-bearing structure consists of large reinforced concrete wall panels and concrete floorslabs.

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4.3 Type of Structural SystemMaterial Type of

Load-BearingStructure

# Subtypes

Masonry Stone masonrywalls

1 Rubble stone (field stone) in mud/lime mortar or withoutmortar (usually with timber roof)

2 Massive stone masonry (in lime or cement mortar)Earthen walls 3 Mud walls

4 Mud walls with horizontal wood elements5 Adobe block or brick walls6 Rammed earth/Pise construction

Unreinforced brickmasonry walls

7 Unreinforced brick masonry in mud or lime mortar8 Unreinforced brick masonry in mud or lime mortar with

vertical posts9 Unreinforced brick masonry in cement or lime mortar

(various floor/roof systems)Confined masonry 10 Confined brick/block masonry with concrete posts/tie

columns and beamsConcrete blockmasonry walls

11 Unreinforced in lime or cement mortar (various floor/roofsystems)

12 Reinforced in cement mortar (various floor/roof systems)13 Large concrete block walls with concrete floors and roofs

Concrete Moment resistingframe

14 Designed for gravity loads only (predating seismic codes i.e.no seismic features)

15 Designed with seismic features (various ages)16 Frame with unreinforced masonry infill walls17 Flat slab structure18 Precast frame structure19 Frame with concrete shear walls-dual system20 Precast prestressed frame with shear walls

Shear wall structure 21 Walls cast in-situ22 Precast wall panel structure X

Steel Moment resistingframe

23 With brick masonry partitions24 With cast in-situ concrete walls25 With lightweight partitions

Braced frame 26 Concentric27 Eccentric

Timber Load-bearingtimber frame

28 Thatch29 Post and beam frame30 Walls with bamboo/reed mesh and post (wattle and daub)31 Wooden frame (with or without infill)32 Stud wall frame with plywood/gypsum board sheathing33 Wooden panel or log construction

Various Seismic protectionsystems

34 Building protected with base isolation devices or seismicdampers

Other 35

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4.4 Type of FoundationType Description

Shallow Foundation Wall or column embedded in soil, without footingRubble stone (fieldstone) isolated footingRubble stone (fieldstone) strip footingReinforced concrete isolated footingReinforced concrete strip footing XMat foundation XNo foundation

Deep Foundation Reinforced concrete bearing pilesReinforced concrete skin friction pilesSteel bearing pilesWood pilesSteel skin friction pilesCast in place concrete piersCaissons

Other

4.5 Type of Floor/Roof SystemMaterial Description of floor/roof system Floor Roof

Masonry VaultedComposite masonry and concrete joist

StructuralConcrete

Solid slabs (cast in place or precast)Cast in place waffle slabsCast in place flat slabsPrecast joist systemPrecast hollow core slabsPrecast beams with concrete toppingPost-tensioned slabs

Steel Composite steel deck with concrete slabTimber Rammed earth with ballast and concrete or plaster finishing

Wood planks or beams with ballast and concrete or plaster finishingThatched roof supported on wood purlinsWood single roofWood planks or beams that support clay tilesWood planks or beams that support slate, metal asbestos-cement or plasticcorrugated sheets or tilesWood plank, plywood or manufactured wood panels on joists supported bybeams or walls

Structuralconcrete

Precast solid slab panels X X

Additional Comments: Floor/roof considered to be a rigid diaphragm.

4.6 Typical Plan DimensionsLength: 39.6 - 39.6 metersWidth: 39.6 - 39.6 meters

4.7 Typical Number of Stories5 - 9

4.8 Typical Story Height3 meters

4.9 Typical Span2.7 meters

Additional Comments: For cross walls: 3.6 m or 2.7 m. For longitudinal walls: 5.4 m.

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4.10 Typical Wall DensityThe ratio of total wall area/plan area is about 0.14. Wall density in two principal directions is not equal; inone of the directions wall density is less by 20 to 30% as compared to the other direction.

4.11 General Applicability of Answers to Questions in Section 4This contribution describes prefabricated building construction. Buildings of this type were standardized inthe dimensions and therefore this form addresses generic structural type rather than the description of asingle building only.

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5 Evaluation of Seismic Performance and Seismic Vulnerability

5.1 Structural and Architectural Features: Seismic ResistanceStructural/ArchitecturalFeature

Statement True False N/A

Lateral load path The structure contains a complete load path for seismic force effects fromany horizontal direction that serves to transfer inertial forces form thebuilding to the foundation.

X

Buildingconfiguration

The building is regular with regards to both the plan and the elevation. X

Roof construction The roof diaphragm is considered to be rigid and it is expected that the roofstructure will maintain its integrity, i.e.. shape and form, during anearthquake of intensity expected in this area.

X

Floor construction The floor diaphragm(s) are considered to be rigid and it is expected that thefloor structure(s) will maintain its integrity, during an earthquake of intensityexpected in this area.

X

Foundationperformance

There is no evidence of excessive foundation movement (e.g. settlement)that would affect the integrity or performance of the structure in anearthquake.

X

Wall and framestructures-redundancy

The number of lines of walls or frames in each principal direction is greaterthan or equal to 2.

X

Wall proportions Height-to-thickness ratio of the shear walls at each floor level is: 1) Lessthan 25 (concrete walls); 2)Less than 30 (reinforced masonry walls); 3)Less than 13 (unreinforced masonry walls).

X

Foundation- wallconnection

Vertical load-bearing elements (columns, walls) are attached to thefoundations; concrete columns and walls are doweled into the foundation.

X

Wall-roofconnections

Exterior walls are anchored for out-of-plane seismic effects at eachdiaphragm level with metal anchors or straps.

X

Wall openings The total width of door and window openings in a wall is: 1) for brickmasonry construction in cement mortar: less than 1/2 of the distancebetween the adjacent cross walls; 2) for adobe masonry, stone masonryand brick masonry in mud mortar: less than 1/3 of the distance between theadjacent cross walls; 3) for precast concrete wall structures: less than 3/4 ofthe length of a perimeter wall.

X

Quality of buildingmaterials

Quality of building materials is considered to be adequate per requirementsof national codes and standards (an estimate).

X

Quality ofworkmanship

Quality of workmanship (based on visual inspection of few typical buildings)is considered to be good (per local construction standards).

X

Maintenance Buildings of this type are generally well maintained and there are no visiblesigns of deterioration of building elements (concrete, steel, timber).

X

Other

Additional Comments: The building maintenance level is variable. The majority of buildings in Bishkek arerather well maintained, however maintenance is not equally good in other cities.

5.2 Seismic FeaturesStructural Element Seismic Deficiency Earthquake-Resilient Features Earthquake Damage PatternsWall Panel joints; quality of construction,

especially welding of reinforcing barsfrom the adjacent panels and filling thegaps between the panels with concreteis not satisfactory in some cases.

Due to a large number and uniformdistribution of panel joints existing inone building, deficient construction ofsome joints does not have a majorimpact on the overall seismic resistancein the building as a whole.

Cracking in joints and panels.

Roof and Floors Panel joints; quality of construction,especially welding of reinforcing barsfrom the adjacent panels and filling thegap between the panels with concrete isnot satisfactory in some cases.

Due to large number and uniformdistribution of panel joints in a building,deficient construction of some jointsdoes not have a major impact on theoverall seismic resistance of thebuilding as a whole.

Cracking in the joints and panels

Roof and floorsOther

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5.3 Seismic Vulnerability RatingVulnerability

High (Very PoorSeismicPerformance)

Medium Low (ExcellentSeismicPerformace)

A B C D E FSeismic

Vulnerability Class< 0 >

0 - probable value< - lower bound> - upper bound

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6 Earthquake Damage Patterns

6.1 Past Earthquakes Reported To Affect This ConstructionYear Earthquake Epicenter Richter magnitude(M) Maximum Intensity (Indicate

Scale e.g. MMI, MSK)1988 Spitak 7.4 91986 Karakum 6.8 7

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7 Building Materials and Construction Process

7.1 Description of Building MaterialsStructural Element Building Material Characteristic Strength Mix Proportions/ Dimensions CommentsWalls Reinforced

concreteConcrete:20-30 MPa (cubecompressive strength) Steel:295-390 MPa (Yield strength)

Foundations Reinforcedconcrete

Concrete: 20-30 MPa (cubecompressive strength) Steel:295-390 MPa (Yield strength)

Roof and floors Reinforcedconcrete

Concrete: 20-30 MPa (cubecompressive strength) Steel:295-390 MPa (Yield strength)

OtherOther

7.2 Does the builder typically live in this construction type, or is it more typicallybuilt by developers or for speculation?Anyone can live in buildings of this construction type.

7.3 Construction ProcessTypically, buildings of this type are constructed by construction companies specializing in prefabricatedconstruction. Typical equipment used for the erection includes crane, welding equipment, and scaffolding.Panels are cast in the plants using a mechanized process. Steam is used in the panel manufacturingprocess. Typically, distance from a plant to a site is not more than 100-150 km. The panels aretransported from a plant to the construction site by means of special vehicles.

7.4 Design/Construction ExpertiseExpertise related to design and construction of this type according to the legal system of Kyrgyzstan wasavailable. Designs for buildings of this type were prepared by specialized design institutes with expertisein this type of construction.

7.5 Building Codes and StandardsYes No

Is this construction type addressed by codes/standards? X

Title of the code or standard: SNiP II-7-81. Building in Seismic Regions. Design code.When was the most recent code/standard addressing this construction type issued? 1981

7.6 Role of Engineers and ArchitectsDesign for this construction type was done completely by engineers and architects. Engineers played aleading role in each stage of construction.

7.7 Building Permits and Development Control RulesYes No

Building permits are required XInformal construction XConstruction authorized per development control rules X

7.8 Phasing of ConstructionYes No

Construction takes place over time (incrementally) XBuilding originally designed for its final constructed size X

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7.9 Building MaintenanceWho typically maintains buildings of this type?Builder XOwner(s) XRenter(s)No oneOther

7.10 Process for Building Code EnforcementA building permit will be given if the design documents have been approved by the State Experts. StateExperts check the compliance of design documents with the pertinent Building Codes. According to thebuilding bylaws, a building cannot be occupied without the formal approval of a special committee. Thecommittee gives the approval if the design documents are complete and the construction has beencarried out in compliance with the Building Codes.

7.11 Typical Problems Associated with this Type of ConstructionInadequate quality of panel joints due to poor construction practice: inappropriate density of concrete inpanel joints (not meeting the specifications), nonaligned reinforcement bars from adjacent panels thatneed to be joined together by welding, poor quality of welding.

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8 Construction Economics

8.1 Unit Construction Cost (estimate)For load-bearing structure only (without finishes) about 150-200 US$/m².

8.2 Labor Requirements (estimate)For load-bearing structure only (depending on the number of stories and plan area), the constructionwould take from 1 to 6 months for a team of 15 workers.

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9 Insurance

9.1 Insurance IssuesYes No

Earthquake insurance for this construction type is typically available XInsurance premium discounts or higher coverages are available for seismicallystrengthened buildings or new buildings built to incorporate seismically resistantfeatures

X

9.2 If earthquake insurance is available, what does this insurance typicallycover/cost?

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10 Seismic Strengthening Technologies

10.1 Description of Seismic Strengthening ProvisionsType of intervention Structural Deficiency Description of seismic strengthening provision usedRetrofit(Strengthening)

Cracks in joints and panels -Installation of reinforced concrete bushing key; - Gunite applied on thepanel surface; - Crack injection by means of polymers.

Additional Comments: Some recommended methods for seismic strengthening are: installation ofreinforced concrete bushing keys, applying reinforced gunite on panel surface, injection of polymers incracks. It is usually not required to strengthen buildings of this type. Poor quality of construction isuncommon and does not significantly influence the reliability of buildings. There is some experience withstrengthening the existing load-bearing structures in Kyrgyzstan. In Uzbekistan, there is experience withstrengthening the buildings damaged in the 1978 Gazly earthquake; there, damaged buildings had beenconstructed without earthquake-resistant features (as the area was thought to be of low seismic risk i.e.seismicity 6 on 12 intensity scale).

10.2 Has seismic strengthening described in the above table been performed indesign practice, and if so, to what extent?No.

10.3 Was the work done as a mitigation effort on an undamaged building, or asrepair following earthquake damage?

10.4 Was the construction inspected in the same manner as new construction?

10.5 Who performed the construction: a contractor, or owner/user? Was anarchitect or engineer involved?

10.6 What has been the performance of retrofitted buildings of this type insubsequent earthquakes?

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11 ReferencesKing, Stephanie, Vitaly Khalturin and Brian E. Tucker (1996). Seismic Hazard and Buildings Vulnerabilityin Post-Soviet Central Asia Republics. Proceedings of the NATO Advanced Research Workshop onEarthquake Risk Management Strategies for Post-Soviet Central Asian Republics, Almaty, Kazakhstan,1996. Kluwer Academic Publishers, Dordrecht, Netherlands.

Uranova, S.K., and Imanbekov, S.T. (1996). Building and Construction Design in Seismic Regions-.Handbook. Kyrgyz NIIP Stroitelstva, Building Ministry Kyrgyz Republic, Bishkek, Kyrgyz Republic.

Imanbekov, S., Uranova, S., and Iwan. W. Earthquake Resistance of Multi-Story Residential Buildings inCentral Asian Capital Cities. Seismic Hazard and Building Vulnerability in Post-Soviet Central AsianRepublics (Stephanie A. King, Vitaly I. Khalturin and Brian E. Tucker-Editors), NATO ASI Series 2.Environment - Vol.52, Klywer Academic Publishers, The Netherlands, 1999.

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12 ContributorsName Svetlana Uranova Ulugbek T. BegalievTitle Engineer Head of DepartmentAffiliation KNIIPCAddress 107-1222 Harwood Street Vost Prom ZoneCholponatisky 2City Vancouver, BC BishkekZipcode V6E 152 720571Country Canada KyrgyzstanPhone 604-696-0563 996-3312-237564FaxEmail uransv@yahoo.com utbegaliev@yahoo.comWebpage

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13 Figures

FIGURE 1A: Typical Building

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FIGURE 1B: Typical Building

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FIGURE 2: Key Load-Bearing Elements

FIGURE 3: Plan of a Typical Building

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FIGURE 4A: Critical structural details - typical floor panel construction

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FIGURE 4B: Precast interior wall panel with steel dowels and grooves

FIGURE 4C: Precast interior wall panel with a door opening

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FIGURE 4D: Horizontal section of an exterior wall panel connection

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FIGURE 4E: Vertical section of an exterior wall panel connection

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FIGURE 4F: Horizontal section of an interior wall panel connection

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FIGURE 4G: Vertical section of an interior wall panel connection

FIGURE 4H: Building Under Construction, Showing Panel Connections (Source: Imanbekov, Uranovaand Iwan, 1999)

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FIGURE 4I: Building Under Construction With Exposed Vertical Panel Joint (Source: Imanbekov, Uranovaand Iwan, 1999)

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