This is a typical multi-unit residential building in Turkey. It is a five story reinforced concrete frame building with unreinforced masonry infill partitions in the upper stories and a weak-open first floor. (Comartin, 2009). The reinforced concrete c...

Prepared By: Miguel Robles
Occupancy: Residential
Year Built:
Height: 15 m
Number of stories: 5
Stories below ground: 0
Size: 1360 sqm
Original Code:
Modification: Unknown
Year Modified:
Code of Modification:
Lateral Load System: MomentFrame
Other Load System:
Vertical Load System: Slabl_Beams_Columns
Other Vertical Load System:
Foundation : Mat
Other Foundation : with concrete beams grid
Country: Turkey
State: Sakarya
City: Ozanlar
Street: Ak Sk 47, Seker Mh., 54000
Latitude: 40.785377
Longitude: 30.389769


 

5-story Beskat

Earthquake Information

 

 

Earthquake Date 36389
Moment Magnitude 7.6
Epicentral Distance 44.6
Local Intensity IX MMI
Site Description Adapazari is located on an alluvial plain approximately 30 m above the sea level. It is understood that large part of the city has been built on reclaimed land formed over a swamp. The plain is underlain by Quaternary Age alluvial deposits consisting of alternating layers of gravel, sand, silt and clay deposited by the Sakarya and Mudurnu rivers. The ground water level is typically very shallow and varies between 0.5 m and 3.0 m below ground level. (EEFIT, 2003)
PGA Lateral 0.41 (g)
PGA Vertical 0.26 (g)
SaT
Ground motion recording stations SKR - Turkish National Strong Motion Network station, Adapazari.
Distance to station None
Station Latitude 40.737
Station Longitude 30.384
Ground Motion Summary The earthquake occurred in western Turkey. The Anatolian Block is compressed by African and Arabian Plates from the south and Eurasian Plate from the north. This compression is responsible for complex deformation of the North Anatolian Fault Zone that causes major earthquakes along the fault. The epicenter of this earthquake (40.75N, 29.86E) was located 11 km southeast of the city of Izmit with a focal depth of 17.0 km. Initial field observations indicate that the earthquake produced at least 60 km of surface rupture and right-lateral offsets as large as 2.7 m. The strong motion instrument located in Adapazari recorded peak ground accelerations of 0.41g horizontal and 0.26g vertical.

 

Damage Information

 

 

Performance summary

Although it did not collapse, the building was severely damaged. The most severe damage was found in the columns of the lower floor which had fewer unreinforced masonry partitions than the upper floors. (Comartin, 2009).

Damage state description

The ground floor was the most severely damaged. Most of the columns presented shear or flexure-shear failures, crushed concrete core, spalling concrete or rebar buckling. The same failure patterns were present in the upper floors at a smaller scale. Unreinforced masonry partitions attached to the frames sustained severe damage and cause damage to captive columns and beams. The roof wood structure completely collapsed.

Summary of causes of damage

1. Poor design and construction resulted in insufficient lateral resistance in the framing system. 2. Omitting walls at the ground floor triggered a large dynamic loading on the bare frame at the ground-floor level causing weak-story effect. 3. The wall-like columns are shear critical in the direction of their long axis and fall into flexure-shear controlled or shear controlled category. 4. Transverse reinforcing is very light resulting in many shear and flexure-shear critical column components. 5. The quality of the concrete and the poor detailing of the reinforcement detract from the ductility required by the frame to resist repeated cycles. 6. Inadequate separation between frames and masonry infill allowed damage to the infill walls.

Observed Design and Construction Characteristics

 

Construction Quality

MaterialsNotesContribution to Damage
Concrete
Reinforcing steel Smooth bars

ExecutionNotesContribution to Damage
Conveyance/placement of concrete
Rebar
Field variance with design documents
OtherNotesContribution to Damage
Other Factors Construction Quality

Configuration

Plan IrregularitiesNotesContribution to Damage
Torsion Irregular framing configuration
Perimeter boundary
Diaphragm
Out-of-plane offsets in lateral resisting system
Non-orthogonal systems

Vertical IrregularitiesNotesContribution to Damage
Soft story
Weak story Fewer infill walls
Geometric variablility of lateral resisting system
In-plane discontinuity of lateral resisting system
Mass distribution
Setback
Change in stiffness

OtherNotesContribution to Damage
Other Factors Configuration Irregular column proportions and orientation, beams framing eccentrically into the columns

Lateral Load Resisting System‐General

StrengthNotesContribution to Damage
Overall lack of strength

StiffnessNotesContribution to Damage
Extreme Flexibility

Load PathNotesContribution to Damage
Collectors/Struts
Anchorage of nonstructural elements
Out-of-plane capacity of walls
Diaphragm chords
Diaphragm openings

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting System-General Poor detailing of the reinforcement

Lateral Load Resisting System‐Frames

ColumnsNotesContribution to Damage
Shear strength
Flexural strength
Axial load ratio
Vertical load columns drift capacity
Interference of frame action by infill

BeamsNotesContribution to Damage
Strength relative to columns
Shear controlled behavior
Continuity of longitudinal reinforcing
Loss of vertical capacity
Interference of frame action by infill beams

JointsNotesContribution to Damage
Interior
Exterior
Corner

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting System-Frames The wall-like columns are shear critical in the direction of their long axis

Lateral Load Resisting System‐Shear Walls

ShearNotesContribution to Damage
Diagonal tension/compression
Sliding Shear
Flexure/shear

FlexureNotesContribution to Damage
Compression zone buckling capacity
Discontinuity of wall
Boundary reinforcing fracture/buckling
Boundary Reinforcing at openings

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting System-Shear Walls

Lateral Load Resisting System‐Infills

InfillsNotesContribution to Damage
Unreinforced
Interference with frame action
Out of plane
Attachment to framing

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting Systems-Infills

Lateral Load Resisting System‐Other

FoundationsNotesContribution to Damage
Liquefaction
Pounding
Surface Rupture

OtherNotesContribution to Damage
Pile/Pier tension capacity

MiscellaneousNotesContribution to Damage
Spread footing capacity
Other Factors Lateral Load Resisting Systems-Other-Foundations

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting Systems-Other-Misc

Repair and Retrofit Information

 

Type of Retrofit or Repair

Unknown

Other Retrofit or Repair

Performance Level

Unknown

Hazard Level

Unknown

Retrofit or Repair Code

Unknown

Other Retrofit or Repair Code

Lateral Analysis

Unknown

Other Lateral Analysis

Design Strategy

Retrofit Summary

References

 

http://www.springer.com/engineering/civil+engineering/book/978-90-481-2680-4
Comartin, C., 2009. "Supplemental Vertical Support as a Means for Seismic Retrofit of Buildings". Seismic Risk Assessment and Retrofitting, Springer 2009. (Chapter 16, pp. 329-342).


http://www.fema.gov/library/viewRecord.do?id=3807
FEMA, 2009. "Effects of Strength and Stiffness Degradation on Seismic Response". FEMA P440A, Applied Technology Council (ATC) and Federal Emergency Management Agency (FEMA). (Appendix F).


http://db.concretecoalition.org/static/data/6-references/TURK006_Reference_01.pdf
Earthquake Engineering Field Investigation Team (EEFIT), 2003. "The Kocaeli, Turkey Earthquake of 17 August 1999". Field report by EEFIT, London, UK.


http://db.concretecoalition.org/static/data/6-references/TURK006_Reference_02.pdf
Gulkan, P., Aschheim, M., Spence, R., 2002. Reinforced concrete frame building with masonry infills. Housing Report on Turkey, World Housing Encyclopedia, Earthquake Engineering Research Institute (EERI) and International Association for Earthquake Engineering (IAEE).


http://db.concretecoalition.org/static/data/6-references/TURK001_Reference_01.pdf
Bayhan, B., 2010. "Buildings under recurring near-field earthquakes". Ph.D. Thesis, Middle East Technical University, Ankara, Turkey. (page 63)


United States Geological Survey (USGS). "Magnitude 7.6 TURKEY, 1999 August 17 00:01:39 UTC". Historic Earthquakes, 2012. http://earthquake.usgs.gov/earthquakes/eqarchives/year/1999/1999_08_17.php


United States Geological Survey (USGS), 2008. "USGS ShakeMap: Kocaeli, Turkey". ShakeMap Atlas, 2012. http://earthquake.usgs.gov/earthquakes/shakemap/atlas/shake/199908170001/