The building is main part of the typical branch office of the MPWR which is a five-building complex designed in the 1970's and constructed in the 1980s. There are four service buildings in addition to the main building. All buildings are separated 50 mm b...

Prepared By: Miguel Robles
Occupancy: PublicGovernment
Year Built: 1980
Height: 16.6 m
Number of stories: 5
Stories below ground: 0
Size: 1300 sqm
Original Code: 1975 Turkish (TEC 1975)
Modification: none
Year Modified: N/A
Code of Modification: N/A
Lateral Load System: MomentFrame
Other Load System:
Vertical Load System: Two-way slab and beams with columns
Other Vertical Load System:
Foundation : Mat
Other Foundation :
Country: Turkey
State: Bolu
City: Bolu
Street: Sehitler Cd. and Mezarliklar Md, Kltr Mh., 14300
Latitude: 40.746111
Longitude: 31.606943


 

MPWR - Bolu

Earthquake Information

 

 

Earthquake Date 36476
Moment Magnitude 7.2
Epicentral Distance 37.7
Local Intensity VIII MMI
Site Description "Soil at the surface was silt-clay. The recording station was on the softest, deepest sediments in the Bolu valley. The soil type was classified as Soil according to Kalkan and Glkan (2004). As a separate note, the recording station and so the building were situated in a localized pocket of the worst damage in Bolu (Akkar and Glkan 2002)". (Bayhan, 2010).
PGA Lateral 0.82 (g)
PGA Vertical None (g)
SaT
Ground motion recording stations MPWR Building, Bolu
Distance to station 0
Station Latitude 40.746
Station Longitude 31.607
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 (40.81N, 31.19E) was located 38 km west of Bolu city with a focal depth of 10.0 km. After the earthquake, a 40 km-long surface break was observed along the east-west Dzce fault and the maximum right-lateral surface offset was about 5m. The strong motion instrument located in Bolu records peak ground accelerations of 0.75g north-south and 0.82g east-west.

 

Damage Information

 

 

Performance summary

The building sustained major damage that was judged to represent a "life safety" level of performance. The structural damage was concentrated in the lowest three stories. Damage in the upper two stories consisted of cracking in partition walls and nonstructural damage. The building was demolished in 2009 following a protracted court ruling because it was initially judged as unsafe for occupancy. (Bayhan, 2010).

Damage state description

The building sustained major damage that consisted of shear failures in infill walls and captive columns, shear cracks in the columns, cracking and collapse of supporting infill walls at the roof, and structural damage due to pounding. Column damage consisted essentially of shear cracks. Beams in the bottom three floors suffered flexural cracking in different intensities. Nonstructural damage was noticeable in the upper two stories: cracking in the plaster was observed and damage in the roof consisted of cracking and collapse of the support walls. (Bayhan, 2010).

Summary of causes of damage

1. Lack of seismic design calculation: The 1975 seismic code did not have some of the features that the later versions did, but the principal culprit here was the captive columns facing the inner courtyard. They failed, leading to unsymmetrical drifts on one face of the building that no intervention could correct. 2. The presence of in-fill walls attached to the frames created captive columns and allowed damaged to the walls. 3. Smooth bars and constructions practices permitted formation of large cracks in the columns. 4. Inadequate seismic joints allowed pounding between adjacent buildings.

Observed Design and Construction Characteristics

 

Construction Quality

MaterialsNotesContribution to Damage
Concrete As-built concrete strength (20 MPa) higher than specified (14 MPa).
Reinforcing steel Smooth bars

ExecutionNotesContribution to Damage
Conveyance/placement of concrete
Rebar Concrete cover Ties spacing
Field variance with design documents Longitudinal reinforcement in columns
OtherNotesContribution to Damage
Other Factors Construction Quality Inadequate confinement and lateral reinforcement

Configuration

Plan IrregularitiesNotesContribution to Damage
Torsion
Perimeter boundary Reentrant corner at L-shaped columns
Diaphragm
Out-of-plane offsets in lateral resisting system
Non-orthogonal systems

Vertical IrregularitiesNotesContribution to Damage
Soft story
Weak story
Geometric variablility of lateral resisting system
In-plane discontinuity of lateral resisting system
Mass distribution
Setback
Change in stiffness Except for the L-shaped corner columns, sizes and longitudinal reinforcement in these members decrease progressively from lower to the upper stories. (Bayhan, 2011).

OtherNotesContribution to Damage
Other Factors Configuration Beams framing perpendicularly to L-shaped column flanges

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 Design level surpassed by large margin

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

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 Unintentional short column due to hollow bricks

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

None (demolished/abandoned)

Other Retrofit or Repair

Performance Level

NA

Hazard Level

NA

Retrofit or Repair Code

NA

Other Retrofit or Repair Code

Lateral Analysis

NA

Other Lateral Analysis

Design Strategy

Retrofit Summary

References

 

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.


http://earthquakespectra.org/doi/abs/10.1193/1.3607987
Bayhan, B., and Glkan, P., 2011. "Buildings Subjected to Recurring Earthquakes: A Tale of Three Cities". Earthquake Spectra27, pp. 635-659.


http://eqs.eeri.org/resource/1/easpef/v16/iS1/p1_s1?isAuthorized=no
Lettis, W. et al., 2000. "Geology and Seismicity". Earthquake Spectra, Supplement A to Vol. 16, pp. 1-9.


http://db.concretecoalition.org/static/data/6-references/TURK002_Reference_01.pdf
Sahin, M., and Tari, E., 2000. "The August 17 Kocaeli and the November 12 Duzce earthquakes in Turkey". Istanbul Technical University, Istanbul, Turkey.


United States Geological Survey (USGS), 2008. "USGS ShakeMap: Duzce, Turkey". ShakeMap Atlas, 2012.http://earthquake.usgs.gov/earthquakes/shakemap/atlas/shake/199911121657/


"Turkey". 40.81 N and 31.11 E. Google Earth/USGS, 2012.