Description

The World Housing Encyclopedia (WHE) Report Database contains 130 reports on housing construction types in 43 seismically active countries. Each housing report is a detailed description of a housing type in a particular country. The description is prepared from a number of standard closed-ended questions and some narrative that have been provided by report authors. Each report has five major categories including architectural and structural features; Building Materials and Construction Process; Socio-economic Issues; Past Performance In Earthquakes, Seismic Features and Vulnerability; and Retrofit. All of the housing reports in this database have been contributed by volunteers. If you are interested in writing a housing report please contact the WHE Editorial Board.

About

The World Housing Encyclopedia (WHE) is a collection of resources related to housing construction practices in the seismically active areas of the world. The mission is to share experiences with different construction types and encourage the use of earthquake-resistant technologies worldwide. The technical activities of the WHE are steered by an international team of 22 professionals specializing in different aspects of seismic safety of buildings and structures. They bring relevant experience from 16 seismically active countries across the world. For more information about the World Housing Encyclopedia, visit http://www.world-housing.net/.

General Information

 

Report #:41
Building Type: Two-story unreinforced brick masonry building with wooden floors
Country: Kyrgyzstan
Author(s): Svetlana Uranova
Ulugbek T. Begaliev
Last Updated:
Regions Where Found: Buildings of this construction type can be found in the cities throughout Kyrgyzstan. It is estimated that around 5% of residential buildings in Bischkek and 5-7% of buildings in other cities are of this type. This type of housing construction is commonly found in urban areas.
Summary:

This is a non-engineered construction practiced in Kyrgyzstan in the ...

Length of time practiced: 76-100 years
Still Practiced: No
In practice as of:
Building Occupancy: Single dwellingResidential, 10-19 unitsMixed residential/commercial
Typical number of stories: 2
Terrain-Flat: Typically
Terrain-Sloped: 3
Comments:


 

Features

 

 

Plan Shape Rectangular, solid
Additional comments on plan shape Typical shape of a building plan for this housing type is rectangular.
Typical plan length (meters) 30
Typical plan width (meters) 12
Typical story height (meters) 3.5
Type of Structural System Masonry: Unreinforced Masonry Walls: Brick masonry in mud/lime mortar
Additional comments on structural system Gravity load-bearing system: Elements of gravity load-resisting system are the same as lateral load-resisting system. Wooden floor beams also carry gravity loads. The beams are supported by the wall; however, without any special anchorage. Typical beam cross-sectional dimensions are: 70-150 mm width and 150-250 mm depth. Wooden floors typically do not have concrete topping. Details of floor structures and wall-floor connections are illustrated in Figure 4. Lateral load-resisting system: The lateral load-resisting system in buildings of this type consists of unreinforced brick masonry walls. Brick masonry walls are usually constructed in mud mortar. Typical wall thickness ranges from 380 mm to 510 mm. Walls are usually perforated with rather large door and window openings. Window and door lintel beams are made of timber board or steel bars embedded in mortar. Typical lintel details are shown in Figure 5. Wooden floors do not act as diaphragms.
Gravity load-bearing & lateral load-resisting systems
Typical wall densities in direction 1 15-20%
Typical wall densities in direction 2 15-20%
Additional comments on typical wall densities The typical structural wall density is up to 20 %. Total wall area/plan area is 15%. The range between the ratios of the area of all the walls in each principal direction divided by the total area of the plan is 7-8%.
Wall Openings Typical size of window openings is 1.2m-1.5m(height) x 1.5-2m (width), and the door openings are: 2m (height)x1m (width). There are 16-20 windows at each floor level in the building. The overall window and door areas constitute around 15% of the overall wall surface area.
Is it typical for buildings of this type to have common walls with adjacent buildings? No
Modifications of buildings Modifications in buildings of this type are common e.g. installation of new doors and windows, new walls and partitions, deletion of doors and windows, demolition of existing load-bearing walls and partitions, construction of new balconies, etc.
Type of Foundation Shallow Foundation: Rubble stone, fieldstone strip footing
Additional comments on foundation
Type of Floor System Other floor system
Additional comments on floor system Timber: wood planks of breams with ballast and concrete or plaster finishing
Type of Roof System Roof system, other
Additional comments on roof system Timber: wood shingle roof
Additional comments section 2 Typical separation distance between buildings: minimum 10 meters

 

Building Materials and Construction Process

 

 

Description of Building Materials


Structural Element Building Material (s)Comment (s)
Wall/Frame Wall: Brick masonry Wall: Characteristic Strength-Rt<30kPa; brick compressive strength is over 750 MPa, and mortar compressive strength of over 50 MPa. Rt= adhesion between mortar and bricks
Foundations Stone
Floors WoodTypically pine or aspen wood
Roof WoodTypically pine or aspen wood
Other

Design Process


Who is involved with the design process? Other
Roles of those involved in the design process
Expertise of those involved in the design process

Construction Process


Who typically builds this construction type? Other
Roles of those involved in the building process In general, this is a non-engineered construction (constructed without qualified technical expertise). Usually an engineer managed the construction of this type.
Expertise of those involved in building process
Construction process and phasing Construction of this type was practised many years ago. Usually an engineer managed the construction; however, construction workers did not have any construction-related experience. In some cases, buildings of this type had been constructed without a proper design documentation. This building is not typically constructed incrementally and is not designed for its final constructed size.
Construction issues

Building Codes and Standards


Is this construction type address by codes/standards? No
Applicable codes or standards
Process for building code enforcement

Building Permits and Development Control Rules


Are building permits required? No
Is this typically informal construction? Yes
Is this construction typically authorized as per development control rules? No
Additional comments on building permits and development control rules

Building Maintenance and Condition


Typical problems associated with this type of construction
Who typically maintains buildings of this type? Owner(s)
Additional comments on maintenance and building condition

Construction Economics


Unit construction cost Cost of load-bearing structure is on the order of 100 US$/sq m.
Labor requirements 10 people need to work for 12-24 months in order to build a building of this type.
Additional comments section 3

 

Socio-Economic Issues

 

 

Patterns of occupancy There are 2-4 housing units per building unit at each floor level. Usually there are 8 - 16 units in each building. One family occupies one housing unit. In general, between 8 to 16 families occupy one building of this type.
Number of inhabitants in a typical building of this construction type during the day 10-20
Number of inhabitants in a typical building of this construction type during the evening/night >20
Additional comments on number of inhabitants
Economic level of inhabitants Low-income class (poor)Middle-income class
Additional comments on economic level of inhabitants 70% poor and 30% middle class inhabitants occupy buildings of this type. Ratio of housing unit price to annual income: 5:1 or worse
Typical Source of Financing Personal savings
Additional comments on financing
Type of Ownership Own outright
Additional comments on ownership
Is earthquake insurance for this construction type typically available? No
What does earthquake insurance typically cover/cost
Are premium discounts or higher coverages available for seismically strengthened buildings or new buildings built to incorporate seismically resistant features? No
Additional comments on premium discounts
Additional comments section 4

 

Earthquakes

 

 

Past Earthquakes in the country which affected buildings of this type


YearEarthquake Epicenter Richter Magnitude Maximum Intensity
1992Suusamir, Kyrgyzstan
1986Kairakuum, Tadjikistan
1988Spitak, Armenia
7.4VII
6.8VII

Past Earthquakes


Damage patterns observed in past earthquakes for this construction type The epicenter of the Suusamir earthquake was in the hilly area (mountains). Maximum earthquake intensity (based on the 12-point intensity scale) was 9. Buildings of this type affected by the earthquake were away from the epicenter, located in the region with intensity 6-7 on the same 12-point intensity scale. In the Kairakum earthquake, intensity reported in the cities (where this type of construction is found) was 6-7. Most buildings of this type suffered various extent of damage to masonry walls. Buildings of this type were also damaged in the 1988 Spitak, Armenia earthquake (see Figure 6).
Additional comments on earthquake damage patterns Overall damage patterns observed in past earthquakes for this type of construction included damage to the walls or complete collapse of buildings; the extent of damage depends on the direction of seismic waves, earthquake intensity, and pier dimensions. Wall failure was due to in-plane or out-of-plane shear, more often as a result of out-of-plane shear.

Structural and Architectural Features for Seismic Resistance


The main reference publication used in developing the statements used in this table is FEMA 310 “Handbook for the Seismic Evaluation of Buildings-A Pre-standard”, Federal Emergency Management Agency, Washington, D.C., 1998.

The total width of door and window openings in a wall is: For brick masonry construction in cement mortar : less than ½ of the distance between the adjacent cross walls; For adobe masonry, stone masonry and brick masonry in mud mortar: less than 1/3 of the distance between the adjacent cross walls; For precast concrete wall structures: less than 3/4 of the length of a perimeter wall.
Structural/Architectural Feature Statement Seismic Resistance
Lateral load pathThe structure contains a complete load path for seismic force effects from any horizontal direction that serves to transfer inertial forces from the building to the foundation.FALSE
Building Configuration-VerticalThe building is regular with regards to the elevation. (Specify in 5.4.1)TRUE
Building Configuration-HorizontalThe building is regular with regards to the plan. (Specify in 5.4.2)TRUE
Roof ConstructionThe roof diaphragm is considered to be rigid and it is expected that the roof structure will maintain its integrity, i.e. shape and form, during an earthquake of intensity expected in this area.FALSE
Floor ConstructionThe floor diaphragm(s) are considered to be rigid and it is expected that the floor structure(s) will maintain its integrity during an earthquake of intensity expected in this area.FALSE
Foundation PerformanceThere is no evidence of excessive foundation movement (e.g. settlement) that would affect the integrity or performance of the structure in an earthquake. FALSE
Wall and Frame Structures-RedundancyThe number of lines of walls or frames in each principal direction is greater than or equal to 2.TRUE
Wall ProportionsHeight-to-thickness ratio of the shear walls at each floor level is: Less than 25 (concrete walls); Less than 30 (reinforced masonry walls); Less than 13 (unreinforced masonry walls);TRUE
Foundation-Wall ConnectionVertical load-bearing elements (columns, walls) are attached to the foundations; concrete columns and walls are doweled into the foundation.FALSE
Wall-Roof ConnectionsExterior walls are anchored for out-of-plane seismic effects at each diaphragm level with metal anchors or straps. FALSE
Wall OpeningsTRUE
Quality of Building MaterialsQuality of building materials is considered to be adequate per the requirements of national codes and standards (an estimate). FALSE
Quality of WorkmanshipQuality of workmanship (based on visual inspection of a few typical buildings) is considered to be good (per local construction standards).FALSE
MaintenanceBuildings of this type are generally well maintained and there are no visible signs of deterioration of building elements (concrete, steel, timber).FALSE

Additional comments on structural and architectural features for seismic resistance
Vertical irregularities typically found in this construction type Other
Horizontal irregularities typically found in this construction type Other
Seismic deficiency in walls - Brick masonry walls have poor shear, tension and compression resistance, and steel reinforcement is generally not provided; - Window and door lintels are made of timber boards or steel bars; - Walls are usually perforated with rather large door and wind
Earthquake-resilient features in walls
Seismic deficiency in frames
Earthquake-resilient features in frame
Seismic deficiency in roof and floors Wood beams are not joined in the rigid diaphragm
Earthquake resilient features in roof and floors
Seismic deficiency in foundation
Earthquake-resilient features in foundation

Seismic Vulnerability Rating


For information about how seismic vulnerability ratings were selected see the Seismic Vulnerability Guidelines

High vulnerabilty Medium vulnerabilityLow vulnerability
ABCDEF
Seismic vulnerability class |- o -|

Additional comments section 5

Retrofit Information

 

Description of Seismic Strengthening Provisions


Structural Deficiency Seismic Strengthening

Additional comments on seismic strengthening provisions Seismic strengthening is not considered feasible for buildings of this type. If strengthening were to be implemented, there would be a need to install new floors, provide jacketing of the walls (on both faces) etc. This is considered to be expensive and therefore the buildings of this type, if severely damaged in an earthquake, are replaced with new buildings. In case of minor damage (e.g. cracks developed in the walls), these cracks are repaired without strengthening.
Has seismic strengthening described in the above table been performed? N/A
Was the work done as a mitigation effort on an undamaged building or as a repair following earthquake damages? N/A
Was the construction inspected in the same manner as new construction? N/A
Who performed the construction: a contractor or owner/user? Was an architect or engineer involved? N/A
What has been the performance of retrofitted buildings of this type in subsequent earthquakes? N/A
Additional comments section 6

 

References

Seismic Hazard and Building Vulnerability in Post-Soviet Central Asia Republics. Nato Series.Netherland.


Buildings and Construction Design in Seismic Regions. Handbook.Bishkek.1996.


Authors



Name Title Affiliation Location Email
Svetlana Uranova Dr., Head of the Laboratory KRSU Kievskai 44, Bishkek 720000 Kyrgyz Republic uransv@yahoo.com
Ulugbek T. Begaliev Head of Department KNIIPC Vost Prom Zone Cholponatisky 2, Bishkek 720571 Kyrgyz Republic utbegaliev@yahoo.com

Reviewers


Name Title Affiliation Location Email
Svetlana N. Brzev Instructor Civil and Structural Engineering Technology, British Columbia Institute of Technology Burnaby BC V5G 3H2, Canada sbrzev@bcit.ca