Simav earthquake and evaluation of existing sample RC buildings according to the TEC-2007 criteria

18 Pages·2013·5.88 MB·English

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Nat. HazardsEarthSyst. Sci.,13,505–522,2013 Natural Hazards O Natural Hazards O
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wdowi:w10.n.5at1-9h4a/znahrdesss-e-1a3rt-h5-0s5y-s2t-0s1c3i.net/13/505/2013/ and Earth System en Ac and Earth System en Ac
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Atmospheric O Atmospheric O
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Chemistry A Chemistry A
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and Physicse and Physicse
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19 May 2011 Ku¨tahya – Simav earthquake and evaluation of Discussions
existing sample RC buildings according to the TECA-tm20o0sp7hcerriict eOpria Atmospheric Op
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Measurement A Measurement A
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M.H.Arslan1,M.Olgun1,M.A.Ko¨rogˇlu2,I.H.Erkan1,A.Ko¨ken1,andO.Tan1 Techniquesce Techniquesce
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1DepartmentofCivilEngineering,SelcukUniversity,42075Konya,Turkey
Discussions
2DepartmentofCivilEngineering,NecmettinErbakanUniversity,42060Konya,Turkey
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Correspondenceto:M.H.Arslan([email protected]) en Biogeosciencesen
Biogeosciences A A
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Received:19October2012–PublishedinNat.HazardsEarthSyst.Sci.Discuss.:– e e
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Revised:25December2012–Accepted:3January2013–Published:25February2013
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Abstract. This study examines the damage caused to rein- 7.2))(ArslanandKorkmaz,2007;CC¸algi˘mataay,t2e0 0e5;Ineletal., e
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forced concrete structures by the 2011 earthquake that oc- 2008; Tan et al., 2008; Adalier and Aydıngu¨n, A2001; Sezen of the Past A
of the Pastc c
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curred in Simav, Turkey. The study briefly reports on post- et al., 2003; Dog˘angu¨n, 2004; Celep et al., 201e1; Kaplan et e
s Discussionss
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earthquakefield observations,tectoniccharacteristics ofthe al.,2004).Themajorityofthesestudiesarerelatedtobuild-
earthquakearea,geotechnicalcharacteristicsofthefield,and ingswithreinforcedconcrete(RC)structuralsystems.How-
seismic characteristics of the earthquake. The main part of ever,mostofthelow-riseresidentialbuildingscOponstructedin Earth System Op
thestudycomprisesafieldstudy,materialexperiments,and villagesandsmalltownsEaraemrtahso Snryyssttruecmtur eens.Therefore, en
A Dynamics A
performance analyses of two reinforced concrete buildings much of the knowledge aboutDTuyrnkiashmeaircthsqucake hazards, c
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thatsurvivedtheearthquakewithmediumleveldamage.The structuraldeficiencies,anderrorsareconcentratesedonRCand Discussionses
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building performance was calculated and assessed accord- masonry structures (Arslan and Korkmaz, 2007; C¸ag˘atay,
ing to the Turkish Earthquake Code requirements for exist- 2005;Ineletal.,2008;Kaltakcıetal.,2007;Tanetal.,2008;
Geoscientific Geoscientific
ing building stock, and recommendations were made based AdalierandAydıngu¨n,2001;Sezenetal.,2003O;Dog˘angu¨n, O
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onthefindings. 2004;Celepetal.,2011;InKsaptrlaunmetealn.,t2a0t0io4;nA erslan,2010). Instrumentation e
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On 19 May 2011 an eaMrthequthakoedwsi tahnmdag Acnitude (Mw) Methods and Ac
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5.7 occurred in Simav, in Ku¨tahya Province, leocated in the e
Data Systemsss Data Systemsss
western part of Turkey. According to the Earthquake De-
1 Introduction partmentoftheDisasterandEmergencyManagementPresi- Discussions
dency(DEMP),theearthquakeoccurredat20:O15localtime GeoscientificO
Turkey is situated in an active earthquake zone and more with epicenter coordinatesGoefo39s.1c3i2e8n◦Nti,fi2c9.pe0820◦E at a pe
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than 90% of its land area is within highly seismic re- depthof24.46km.Theearthquakeresultedin2 Afatalitiesand Model Development A
Model Developmentc c
gions. During the 20th century, Turkey experienced sev- morethan122injuries.Approximately2500afcetershocksoc- ce
s Discussionss
eral moderate to heavy earthquakes that resulted in signif- curred after the main shock (Sandıkkaya et als., 2011; ˙Inel s
icant loss of life and property, and 22 major earthquakes et al., 2011; Kaplan et al., 2011), with a magnitude range
with minimum magnitudes 7 (Mw) caused significant ca- (ML)ofbetween1.3andH4y.8d(Sroanldoıkgkyay aaentdal .,Op2011).After Hydrology and Op
smuaazlt,ie2s00a7n;dC¸eaxgt˘eantasyiv,e20st0r5u;ctIunrealledtaaml.a,g2e0(0A8)r.slTanheanlidteKraoturkre- tihneg ethaerthcqauuasekseoTfutrhkeishdarmEesaeagaerrscthhoen rSsefsyopcseuctsieaeldmlyoRnen AcCunbdueirlsdtianngds-. Earth Systemen Ac
includes many studies of earthquakes and post-earthquake Tama(2012)investigatedthebuSildcinigesnbcyeP2s5-cesrapidassess- Sciencesces
case studies in Turkey because several destructive earth- mentmethod.Themethodshowedthattwoofsthebuildings s
Discussions
quakes have hit the country during the last two decades were in “high risk band”; the other two fell into “detailed
(including1992Erzincan(Mw=6.8),1996Adana–Ceyhan evaluation band”, and the rest were in the “lowOprisk band”. Op
(Mw=6.3),1999Adapazari–Izmit(Mw=7.4),1999Du¨zce So his findings demonstrated that the figure menatched with Ocean Scienceen
(Mw=7.2),2002Afyon–Sultandagi(Mw=6.5),2003Bin- thedamagesobservedOintcheesaitne sSurvceiyeanftcereth Acceearthquake. Discussions Acc
gol (M =6.4), 2010 Elazıg˘ (M =6.0), 2011 Van (M = e e
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PublishedbyCopernicusPublicationsonbehalfoftheEuropeanGeosciencesUnion.
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Solid Earth A A
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The Cryosphere A A
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Fig. 1.

506 M.H.Arslanetal.: 19May2011Ku¨tahya
Fig. 1. Fig. 2.

Fig.2.MajorfaultingsystemintheSimavregion(AFAD,2011).
Fig.1.Majortectonicelementsan ddistributioninTurkey(Adalier

andAydingun,2001).
Fig. 2.
Province (EAF), the Aegean Graben System, the Cyprus–

This study briefly examined structural damage caused by HellenicArc,theCentralAnatolianProvince,andtheBlack
this earthquake event. The seismic characteristics of the Sea region (Sengor et al., 19 85). The tectonics of Turkey
earthquakeweredeterminedbyexaminingtheseismicstruc- is greatly influenced by the movements of the Arabian,
ture and soil features of the region. Soil and material ex- Eurasian, and African plates (Fig. 1). The Arabian plate

perimentsrequiredbyTurkishEarthquakeCode(TEC-2007) moves NE and pushes the Eurasian plate along the Bitlis
normsweremadeintwolow-risebuildingsthatex perienced thrustandfaultzone.Duetothiscontinuingmovementofthe
medium damage. Using the obtained data, the load systems Arabianplate,theAnatolianblockshiftswestwardalongthe

ofthebuildingswereevaluatedtoanalyzestructuralperfor- NorthandNortheastAnatolianfaults.Ontheotherhand,the
mance. The main aim of the study is to compare two sam- African plate moves in the NE direction, colliding with the 32
ple RC buildings located on alluvial soils, which suffered Eurasianplate,andsubductsalongtheCyprus–HellenicArc,
damagebutremainedstanding,andtocriticallyevaluatethe somewhat retarding the westward movement of the Anato-
provisions of the TEC-2007 regulations. For this purpose, lianblockandinitiatingitstendencytorotatetotheSW.The
the seismic performance of the selected buildings obtained interaction of these complex plate motions resulted in sev-
by the non-linear evaluation procedures given in TEC-2007 eralE–Wtrendingblocksboundedbyobliquenormalfaults
has been conducted. Global pe rformance of these buildings insouthwestTurkey.Consequently,thisregioncoveringthe
wasdeterminedfromthemem berperformancesandthean- Cyprus-Hellenic Arc and the Aegean Graben System has
alyticalresultswerecomparedwiththeexperienceddamage veryhighseismicity(Konak,1982).
ofthebuildings.Aftertheasse ssmentacriticalcomparative The Aegean region of Turkey, including Ku¨tahya
evaluationhasbeendonefromtheobtainedresults. Province, is a highly active seismic area and has frequently

been exposed to earthquakes. Ku¨tahya is affected by the
groundmotionsresultingfromtheGediz–Emet,Simav,and
2 Seismicityandgeotechnicalcharacteristics Ku¨tahya fault lines. Throughout history many destructive

earthquakes causing loss of life and property have occurred
2.1 Tectonicsetting in the region (Table 1). The highest magnitude earthquake
recorded in this region was generated by the Gediz fault in

Turkey is located in the eastern Mediterranean segment on March 1970 and resulted in more than 1000 casualties and
theAlpine–Himalayanearthqu akebeltandisfrequentlyex- the total collapse of 3500 buildings. The most recent disas-
posedtodestructiveearthquakes.Accordingtotheseismicity trousearthquakeofKu¨tahya–Simavin2011,approximately
  32
mapofTurkey,95%ofthepopulationand92%ofTurkish 40kmfromtheepicenterofthe1970Gedizearthquake,led
land is within seismically active areas (on seismic zones 1 toconsiderabledamageinSimav,Ku¨tahya.
to4).TheKu¨tahya–Simavregionisinthefirstseismiczone Simav district is located within a collapsed basin (ele-
according to the seismic zoning map of Turkey and has a vation 800m) known as the Simav Graben. Simav Moun-
seismiccoefficientof0.4gaccordingtoTEC-2007. tain extends east–west and is located in the south of Simav.
There are seven major tectonic provinces in Turkey: The most important tectonic feature of the study area is
the North Anatolian Fault (NAF), the Northeast Ana- Simav Fault, an active right strike-slip fault extending ap-
tolian Fault (NEAF), the East Anatolian Contractional proximately 205km length in a general NW–SE direction
Nat. HazardsEarthSyst. Sci.,13,505–522,2013 www.nat-hazards-earth-syst-sci.net/13/505/2013/
M.H.Arslanetal.: 19May2011Ku¨tahya 507
Fig. 3.
Fig. 3.
Table 1. Recent destructive earthquakes in the Aegean region of
Turkey.
Date InstrumentalMagnitude Epicenter
1928 6.2 Emet
1944 6.2 Saphane
1970 7.2 Gediz
1970 5.9 Cavdarhisar
2011 5.7 Simav
(Konak, 1982; Sarog˘lu et al., 1987, 1992). The epicenter of
the 19 May 2011 Simav earthquake was the Simav Fault
Zone. The region includes active fault segments within the
SimavfaultzonewithaNW–SEdirection(Fig.2).Withinthe

month following the earthquake, 1629 aftershocks occurred
aroundtheSimavepicenter.Themagnitudesofmostofthese
Fig.3.Simplifiedgeologicalmap ofSimavanditsvicinity(Inelet
aftershocks (1322) were 3 or less (M≤3). The number of al.,2011).
Fig. 4.
seismogramsoftheearthquakeswhosemagnitudeswerebe-
Fig. 4.
tween3and4(3<M≤4)was292,andthenumberofseis-
mograms of the ones between 4 and 5 (4<M≤5) was 13
(Fig.2).
2.2 Geologicalsetting
The Ku¨tahya–Simav region is characterized by plateaus of
varying heights, with some mountains and hills as well as
largeplains.Bothmountainandhillrangesandlowareasare
oriented in NW–SE direction, which is consistent with the
generalcharacteristicsoftheregion.TheKu¨tahya,Tavs¸anlı,
Altıntas¸, Gediz, Simav, and O¨rencik plains, which are allu-
viumcovered,formthelowerpartsofthisregion.Themain
part of the region consists of Neogene plateaus. Within the
study region, the Neogene series begins with a thick con-
glomerateseriesandcontinueswithclay,marl,andlimestone
Fig.4.Spectralaccelerationvalues forfourearthquakesinTurkey.
series. Despite generally being horizontal, Neogene series

aresometimessloping.Theregionhasmanyblockfaultsas
aresultoftheseNeogeneseries.Tectonicactivitiesaregen- Thisclayedsedimentisupto1 0mthickinsomeplaces,and

erallyobservedinthewestandsouthwestoftheregion.Old
hashighplasticityandlowbearingcapacity.
Neogeneterrestrialsedimentsareobservedinthesoutheast-

ern, northern, and northwestern parts of Simav district. In 2.3 Characteristicsofstrongmotionrecords
addition, pre-Neogene basic rock units of various ages can
befoundacrossawidearea.Thelandisgenerallyroughex- The highest acceleration value of the earthquake was mea-
cept in the northern part of Simav and has many valleys of sured as 103.92cms−2 (gal) i n an E–W direction in Gediz
varying sizes. These valleys are generally filled with young district. As a result of a study based on the 31-km distance

alluviumcarriedbyrivers. fromtheGedizstationtoSimav,Ineletal.(2011)predicted
TheplaininthenorthernpartofSimavdistrictinvolvesal- thegroundaccelerationinanE– Wdirectionas247cms−2at

luvialmaterialwithhighgroundwaterlevel,andthesouthern theepicenter. Spectrumvaluesina N–S directionarelower

partinvolvesrock(limestoneandschist)andslopewashma- than those in an E–W directio n. Maximum ground acceler-
terials (Fig. 3). Until 1960 Simav Lake extended northwest ationpredictedinTEC-2007forthisregionis392.4cms−2.

from Simav city center; after 1960, this lake was dried by Figure 4 shows spectral accele ration with respect to the pe-
openingchannels,leavingblack–darkgreyorganicclay.Af- riodforadampingratioof5% .Itisinferredthattheearth-
ter drying the lake, the site was zoned for co nstruction, and quake impacted structures wit h a fundamental period of up 33
now includes a dense residential area and public buildings. to0.15s.

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  33
508 M.H.Arslanetal.: 19May2011Ku¨tahya
3 Damagetypesinreinforcedconcretestructures
ThetypicalconstructionsinTurkeyareRCmoment-resisting
frames with hollow, unreinforced clay-brick infill panels as
theurbanpartofthisarea.Crackfailuresandcollapseofin-
fill walls, resulting in significant economic loss and human
casualties,areobservedonRCstructures.Mostofthedam-
agetosuchstructuresoccurredinlocationswithalluvialsoil.
TheclaysoilsinthenorthernpartofSimavbearnegative
geotechnicalconditions.Soilamplificationishigherinthese
types of soil during an earthquake. In addition, soil softens
under continuous loads in these types of soils and shearing
resistance parameters (cohesion and angle of internal fric-
tion)decrease.Whenthesitesofstructuraldamageareexam-
ined,itcanbeseenthattheeffectoftheearthquakeextended
to an area of approximately 25km radius from the epicen-
terandthereislessstructuraldamageintheareawith10km
radius(redring)(Fig.5).Oneofthemainreasonswhysignif-
Fig.5.DistributionofdamagedareasinandaroundSimav(Inelet icantdamageswerenotobservedinsettlementareassuchas
al.,2011).
S¸enko¨y, So¨g˘u¨t, and Kapıkaya even though they are close to
theepicenteroftheearthquake,isthatstructuresarelocated
onunitswithtighterandmorerigidgeotechnicalfeatures.
2.4 GeotechnicalaspectofSimavearthquake
In Simav city center, inadequate spacing between neigh-
boring buildings contributed to serious damage to a signifi-
Significant amounts of damage were observed in buildings
cant number of buildings. During the earthquake, hammer-
locatedonclayedunitswithyounglacustrinesediment,even
ing(structurescontactedeachotherduetodifferencesinthe
though they were located away from the epicenter. These
dynamic properties of adjacent buildings) was observed in
regions cover especially the northern part of the center of
many neighboring buildings. Similar to previous studies of
Simav.Instandardpenetrationtests(SPT)conductedinthese
earthquakes in Turkey (Adalier and Aydıngu¨n, 2001; Sezen
clayunits,generalaverageN valuesrangedbetween7and
30
et al., 2003; Dog˘angu¨n, 2004; Celep et al., 2011; Kaplan et
13(Ineletal.,2011).Consideringthesevalues,theunitcan
al.,2004),post-earthquakeobservationsrevealedpoordetail-
beclassifiedasCorDsoilgroupaccordingtodisasterregu-
ing,andalackofappropriatereinforcementwasobservedin
lations.Acceptingthattheunitthicknessdoesnotgenerally
manyRCframedstructuresinSimav.Thewideshearcracks
exceed15meters,territorialsoilclassfallswithintheZ2–Z3
and plastic hinging at column ends indicate that poor de-
interval. In addition, in some regions with low construction
tailing and an insufficient number of column transverse re-
density,astheclayunitthicknessexceeds10–15m,theterri-
inforcements led to catastrophic failure. In Simav a lack of
torialsoilclassisZ3–Z4.Shearwavevelocity(V )measured
s
inthislevelisaround250ms−1.Duetothesefeatures,high stirrupsatthejointswasobserved,makingthebeam-column
joints vulnerable to earthquakes (Sandıkkaya et al., 2011;
soilamplificationvaluesareobservedinthesesettlementar-
˙Inel et al., 2011; Kaplan et al., 2011). The major deficien-
eas.
ciesofreinforcementdetailinginSimavareasfollows:
Many urban and rural settlements, especially in the cen-
ter of Simav, have been settled in graben (sediment) areas.
Moreover,thesesettlementareasarelocatedinlacustrineal-
luvial soil units with high groundwater levels. This geolog- Unsuitable transverse reinforcement (large spacing of
ical structure in settlement areas has become a basic con- stirrups(Fig.6a)andlackof135degreehooksattheend
trolfactorintermsoftheeffectsofearthquakesonbuildings. ofcolumnties)
When the damage distribution in the district was examined,
more damage was observed in the structures located on al- Duringanearthquake,someadditionallateralforcesarein-
luvial soil (plains) compared to those on rock fields in the duced in a structure. These loads increases the shear forces
south.However,theobservationsshowednoadvancedlique- on the structures, so, actually for columns, design of the
factioninSimavplaininthisearthquakeevent. shearreinforcementisessential.Widespacingoflateralties
isacommonshortcomingobservedinSimavRCstructures.
During site observations after earthquakes, it is noted that
thestirrupspacingwasmuchmorethanthemaximumvalue
allowed by the design code TEC 2007. For most of the
damaged columns, no tie spacing of less than 100mm was
Nat. HazardsEarthSyst. Sci.,13,505–522,2013 www.nat-hazards-earth-syst-sci.net/13/505/2013/
M.H.Arslanetal.: 19May2011Ku¨tahya 509
observed. Often unequally spaced ties are between 150mm Insufficientlateraltiesatthebeam–columnjoints
and300mm.
For TEC-2007, “hoops and crossties used in columns, Wide spacing of lateral ties is a common shortcoming ob-
beam-column joints, wall end zones and beam confinement served by authors in Turkish RC structures. During site ob-
zones of all reinforced concrete systems of high ductility servationsafterearthquakes,itisnotedthatthestirrupspac-
level or normal ductility level in all seismic zones shall be ingwasmuchmorethanthemaximumvalueallowedbythe
specialseismichoopsandspecialseismiccrossties”.Special design code (Sandıkkaya et al., 2011; ˙Inel, 2011; Kaplan et
seismic hoops shall always have 135degree hooks at both al.,2011),asseeninFig.6a.Inmostdamagedcolumns,atie
ends. 90-degree hook does not provide effective anchorage spacingoflessthan100mmwasnotobserved.
since it is not embedded in the confined. Unfortunately, in
Simav,90-degreehookshavebeencommonlyobserved.
Using plain rebar for reinforcement (low tensile quality
ofsteelreinforcement)(Fig.9a)
Unconfinedlapsplices
After the earthquakes, especially widespread use of plain-
The strength of the lap splice is very important for the de- rebarcausedbondproblemscoupledwithinsufficientsplic-
velopmentofstrengthandductilityofareinforcedconcrete inglengthshavebeenobservedinmanyRCbuildings.
column.Accordingtotheobservationinthefield,lapsplices In addition to reinforcement detailing deficiencies, low
insubstandardcolumnsweretypicallydesignedascompres- qualityconcretecausedadherenceproblemsinRCmembers,
sion splices with the lap length of about 20 to 24 times bar resultinginplastichinging.
diameter.Thereasonformostobserveddefectsindamaged Tallerfirststoriesanddisuseofwallsforexteriorcladding,
members is because of unconfined lap splices, inadequate inordertousethefirstfloorsasshopsbecauseofhighresi-
anchorage lengths (15–30cm), and lower longitudinal rein- dentialdensitiesinSimavcenter,causedweakandsoftstory
forcementratiosthanconsideredindesign.Alsolapsplices problems. The building in Fig. 6b collapsed as the moment
of a column longitudinal reinforcement should be made, as frame was both flexible and weak in the first story com-
much as possible, within the column central zone. Accord- paredwiththeupperstories.Deformationsareconcentrated
ingtoTEC2007,lapsplicesinmoment-framecolumnswere inthefirststoryofthisbuildingsincethefrontofthebuild-
typically made immediately above the floor framing or the ingwasopenedonthefirststory.Thefirst-storycolumnsin
foundation.So,lapsplicesincolumnswerelocatedinaplas- thisbuildingwereseverelydamagedandleanedontothead-
tichingezonewhichisthemostcriticalpartofRCmembers. jacentbuilding.Softstoryfailuresoccurinbuildingsdueto
thesuddenchangeofstorystiffnesswithopenfrontsonthe
groundfloorortallgroundstory(excessivestoryheightwith
Inadequateanchoragelengths
respecttoothers).Themostcommonexamplesareshopping
malls,offices,andhotels,etc.
Thecompositeactionofconcreteandsteelinreinforcedcon-
Because the length of the columns is less, as seen in
crete structures is provided by bond strength. The required
Fig. 6c, the column becomes stiffer, more rigid in bending
bond strength is achieved by providing sufficient develop-
andreceiveshighershearforceduringanearthquake.Since
ment length. In Turkish Building Code (TS-500-2000) and
themomentarmisshort,theshearforcesincrease.Theshort
TEC-2007minimumdevelopmentlengthl isgiven.
p column problem occurred due to the arrangement of infill
Lackofanchorageofbeamsandinsufficientsplicelengths
walls due to window openings in the base floor. In TEC-
is secondarily affected by low-quality levels of concrete.
2007, where shear force short columns cannot be avoided,
Damage due to poor quality of material was reported in the
very stringent requirements for transverse reinforcement of
earthquake.
shortcolumnsareputforward,whicharetakenintoaccount
for the design of transverse reinforcement of columns. Fig-
Lowerlongitudinalreinforcementratiosthanconsidered ure6cisagoodexampleofthiskindofshortcolumndamage
indesign(Fig.6a) fromSimavEarthquake.
Thelongitudinalrebarratio(ρ )rangesbetween1%and4%
1
4 AshortdescriptionofsurveyedRCbuildings
in TEC-2007. In TEC-2007, to increase the ductility, low
intheregion
steel ratio is encouraged because it is an amplification of a
larger cross section. In the earthquake zone, Fig. 9a shows
More than thirty government buildings were surveyed in
thecolumnswithbuckledlongitudinalbarsbecauseoflower
Ku¨tahyacitycenteranditsdistrictsbyauthors.Surveyteams
reinforcementratioandlackofstirrups.
have conducted necessary measurements and took adequate
concretesamplesandcarriedoutdestructiveaswellasnon-
destructive tests to obtain member sizes, member detailing
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Fig.5.

Fig. 7.

510 M.H.Arslanetal.: 19May2011Ku¨tahya
Fig. 6.

a- Lack of stirrups at b- Failure on first floor c- Short column failure
the joints due to soft story

Fig.6.Threedamagetypesfromepicenterregion. Fig. 8.

Fig. 7.

Fig.8.Buildingfacadeandlateral facade(casestudy1).
  34
Fig.7.Geographicaldistributionsofthebuildingsstudied.
Fig. 8. proximately6.76MPa.Itiswo rthnotingthatthecurrentcode
TEC-2007requiresaminimumof20MPaforthedesignof
buildings. From visual inspect ion, it has been observed that
andthemechanicalpropertiesofthematerials.Asindicated
generally plain bars with a characteristic yield strength of
later,atleastthreecoresamplesperstoryweretakentode-
nearly220MPawereused.
termine the building-specific concrete compressive strength
Themajorityofthesurveyed buildings’structuralsystems
tobeusedintheperformanceanalysis.
weremadeofRCwithvaryingpercentagesinthecolumnand
Allbuildingshaddifferentconstructiondates,numbersof
shear wall area. Since the density of shear walls in a given
stories, and flat areas given in Table 2. The damages in the
principal direction is believed to have a prominent role in

buildings were classified into four ranks during the investi-
theseismicperformanceofthebuildings(ArslanandKork-
gation given in Table 2: (1) light and no damage; (2) mi-
  maz,2007;C¸ag˘atay,2005;Ineletal.,2008;Tanetal.,2008; 35
nor damage; (3) medium damage; (4) major damage. Ge-
AdalierandAydıngu¨n,2001;Sezenetal.,2003;Dog˘angu¨n,
ographical distributions of the buildings studied are shown
2004; Celep et al., 2011; Kaplan et al., 2004), it is not sur-
andmarkedinFig.7.Itisclearlyseenthatallbuildingsare
prising to observe that most of the buildings have no shear
locatedintheearthquakeregion.
walls.
Distribution of concrete compressive strength shown in
Table 2 reveals that the concrete compressive strength was
generallybetween4.9–18.2MPawithanaveragevalueofa p-

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  35
M.H.Arslanetal.: 19May2011Ku¨tahya 511
Table2.Descriptionofgovernmentbuildingssurveyedbytheteam.
Location Construction Construction Numberof Stories Totalarea Numberof Averagecompression Steel Damage
type date story area coresamples resistanceof rebartype type
coresamples(MPa)
KCC RC 1994 5 1097 5485 15 6.3 S220 1
KCC RC 1988 3 188 564 9 11.7 S220 1
KCC RC 1987 5 160 800 15 4.85 S220 1
KCC M 1968 3 145 435 – – – 1
KCC RC 1991 1 263 263 4 9.9 S220 1
KCC M 1957 2 329 658 – – – 1
KCC RC 1975 1 525 525 3 4.8 S220 1
KCC RC 2003 1 616 616 3 18.2 S420 1
Gediz RC 2003 3 300 900 9 12.5 S420 1
Gediz RC 1977 4 120 480 12 5.1 S220 1
Gediz RC 1992 2 300 600 6 4.9 S220 2
Tavs¸anlı RC 1994 5 550 2750 15 8.5 S220 2
Tavs¸anlı RC 1988 5 320 1600 15 7.2 S220 1
Tavs¸anlı RC 1978 3 150 450 9 5.6 S220 1
Tavs¸anlı RC 2000 1 360 360 3 6.4 S220 1
Tavs¸anlı RC 1997 1 174 174 3 8.2 S220 1
Tavs¸anlı RC 1997 2 177 354 3 7.1 S220 1
Emet RC 1986 5 340 1700 18 5.4 S220 1
Simav RC 2008 4 342 1368 12 18.2 S420 1
Simav M 1951 2 216 432 – – – 1
Altıntas¸ RC 1994 2 340 680 6 6.8 S220 2
Domanic¸ RC 1997 2 280 560 6 6.2 S220 1
Hisarcık RC 1999 2 280 560 6 6.4 S220 2
Pazarlar M 1962 1 216 216 – – – 1
Aslanapa RC 2009 2 228 456 6 15.1 S420 1
Dumlupınar M 1987 2 149 298 – – – 1
C¸avdarhisar RC 1996 3 262 540 15 7.9 S220 1
Dumlupınar M 1970 2 160 320 – – – 3
Simav-Case1 RC 1990 5 515 2574 15 8.1 S220 3–4
Simav-Case2 RC 1997 6 282 1696 18 6.7 S220 3–4
Yoncalı M 1993 1 800 800 – – – 2
KCC:KutahyaCityCenter,RC:ReinforcedConcrete,M:Masonry
Fig. 9.
5 SeismicperformanceassessmentofRCbuildings
accordingtoTEC-2007
Within seismic codes, the earthquake safety of exist-
ing RC buildings is determined based on the concept of
performance-based design. Generally this takes the form
of the desired performance outcomes, such as withstanding
minor earthquakes undamaged, withstanding medium-scale
earthquakes with limited damage, and withstanding large-
scale earthquakes without total collapse. The critical out-
come is prevention of total structural collapse. This means
that the upper level withstands total collapse (CP); the sub
level,forthecrucialstructures,maybeslightlydamagedbut
remains fit for immediate occupancy (IO). Between the sub
and upper levels there is a life safety (LS) level situation.
Multiple performance objectives for these levels, including
the seismic transformation periods, have been specified in Fig.9.Filledwalldamage.
Table3. Fig. 10.
In Turkey two main codes influence the design and con-
struction of RC buildings: TEC-2007 and TBC-500-2000. designofcolumn,beam,andshearwallelements.TheTBC
TECincludesproceduresforcalculatingearthquakeloadson includes requirements for the design and detailing of RC
buildingsanddeterminingearthquakeperformanceofexist- components but does not include ductile detailing require-
ing structures. This code includes specifications for ductile mentsforuseinseismicdesign.
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  36
512 M.H.Arslanetal.: 19May2011Ku¨tahya
Table3.StructureperformancebasedondamageinTurkishEarth- seismic performance of buildings can be determined using
quakeCode(TEC-2007). linear or non-linear analysis; the design engineer is free to
utilizeeitherlinearornon-linearanalysisapproaches.Short
Performance Performancecriteria procedure seismic performance assessment of an RC build-
level inginTEC-2007isgivenbelow:
Immediate
1. Collecting data from existing RC building (structural
occupancy(IO) – The ratio of beams in
layout,planandverticaldimensions,numberofstories
Slight Damage (SD) and
andarchitecturalfeaturessuchassoftandweakstories
Moderate Damage (MD)
and overhangs, short column formations etc., obtained
shall not exceed 10% in
anystory. concrete average compressive strength, steel yield
strength,steeltype,stirrupsspacingintheconfinement
– There must not be any
regions,identificationofsoiltype).
columns beyond Slight
Damage(SD).
– There must not be any 2. 3-Dmodelingbyusingobtaineddatafromtheexisting
beams beyond Heavy RCbuilding.
Damage(HD).
3. Performanceanalysisaccordingtotheselectedmethods
LifeSafety
(Linearornon-linear)inthecode.
(LS) – The ratio of beams in
Moderate Damage (MD)
andHeavyDamage(HD)
4. JudgingtheperformanceofexistingRCbuildings.
shall not exceed 30% in
anystory.
– In any story, the shear 5.1 Non-linearseismicperformanceassessment
force carried by columns inTEC-2007
in Heavy Damage (HD)
shall not exceed 20% of The purpose of the non-linear analysis methods is to deter-
storyshear. minethestructuralperformanceofexistingRCbuildingsun-
der seismic loading. In TEC-2007, the earthquake safety of
Collapse existingRCbuildingsisdeterminedbasedonaperformance-
Prevention – The ratio of beams in based design. The non-linear evaluation method considers
(CP) Heavy Damage (HD) the elasto-plastic behavior of the structural system and the
must not exceed 20% in mainapplicationprocedureisincrementalequivalentseismic
anystory. analysisaccordingtothesinglemode.
– In any story, the shear The objective is to carry out the non-linear static analy-
force carried by column sisunderincrementallyincreasingseismicforces,distributed
that passed Slight Dam- in accordance with the dominant mode shape in the earth-
age(SD)mustnotexceed quakedisplacement,untildemandisreached.Internalmem-
30%ofstoryshearforce. berforcesandplasticdeformationsarecalculatedatthede-
mand level. After the plastic rotation demands of ductile
Collapse members are calculated, these values are compared and de-
(C) – If the failure can not be finedinTable4.
prevented,itisunderfail- Theseismicperformanceoftheload-bearingsystemisde-
urecondition. finedasthesumofseismicdamagelevelsofthestructuralel-
ements(e.g.,beamsandcolumns)thatformtheload-bearing
system. As part of the static pushover analysis, it is neces-
sarytodefinethecross-sectionaldamagelevelaccordingto
the deformation of each of the structural elements in order
When a short history of earthquake codes is considered, todeterminetheglobalperformanceoftheload-bearingsys-
the earthquakes in Turkey and the code revisions occur at tem. Table 4 shows cross-sectional damage types according
similar times. The recently published version of the TEC- toTEC-2007.
2007 includes seismic performance evaluation and seismic TEC2007definestheperformancelimitsofdeformations
retrofitting sections that are parallel to those in FEMA-356 ofRCelementsasmaximumunitdeformations,calculatedin
andFEMA-440.LikeFEMA-356,TEC-2007statesthatthe concreteandrebarinthesection.Limitvaluesgiveninunit
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Fig. 9.
M.H.Arslanetal.: 19May2011Ku¨tahya 513
Table4.Cross-sectionaldamagelevels.
Cross-sectionaldamagelevel Maximumstrainforconcrete(εc) Maximumstrainforsteel(εs)
SlightDamage(SD) 0.0035 0.010
(cid:16) (cid:17)
ModerateDamage(MD)* 0.0035+0.01 ρs ≤0.0135 0.040
ρsm
(cid:16) (cid:17)
HeavyDamage(HD)** 0.004+0.014 ρs ≤0.018 0.060
ρsm
∗and∗∗:Deformationvaluesintheouterfiberofthestirrup.
Fig. 10.
deformation terms were defined in terms of plastic bending
by using moment-bending relationships calculated primar-
ily for the section. The plastic bend value is determined ac-
cordingtowhetherconcreteorsteelfiberreachestheabove-
mentioned limit values first. The plastic bend value is then
multiplied by the plastic hinge length (L =0.5h) given in
p
TEC-2007 in order to obtain plastic bending. In the equa-
tion given in Table 4, ρ is the volume ratio of minimum
sm
transversereinforcementintheconfinementzone,calculated
accordingtoTEC-2007[13];ρ isthevolumeratiooftrans-
s
versereinforcementintheexistingsection.
Pre-yieldlinearbehaviorofreinforcedconcretesectionis
representedbycrackedsections,whichis0.4EI forflexural
o
members(suchasbeams),andvariesbetween0.40–0.80EI
o
foraxialloadedcolumns.Intheanalyses,strainhardeningin
theplastichingerangecanbeignored.
Fig.10.Filledwalldamage.

6 Casestudies
were 30cm×50cm, 50cm× 60cm, 30cm×55cm, and
25cm×50cm rectangular sections. RC shear wall existed
Thesamplebuildingshavebeenselectedfromthesurveyed

only in the elevator shaft in lead system. Beams were 20
buildingsintheregion.Thesamplebuildingsthathavebeen
cm×60cm and 25cm×60cm. Story heights were 3.00m
explainedindetailwerethebestexamplesoftheirstructural
in the basement, 4.00m in the ground story, 2.25m in the
typeamongthemorethanthirtybuildings.Thebuildingsde-
installationstoryand3.20min eachtypicalstory.
signed and constructed before the TEC-1998 seismic code
Non-loadpartitionwallswereparticularlybadlydamaged
havesimilarstructuraldeficienciesobservedaftertheearth-

in the earthquake. Partition walls were separated from the
quake in Turkey. The structural system and the geometry
of these buildings are thought to represent the current RC frame due to both in-plane a nd out-of-plane movements.
Damagewasespeciallyseverearoundthewallsofsubfloors
structural stock of Turkey. The sample buildings have been
(Figs. 9 and 10). The architec t of the project removed sig-
markedinboldinTable2.
nificant parts of the ground story walls due to the projected

6.1 Casestudy1 usage of the building even though the project originally in-
cludedthem.
6.1.1 Briefdescriptionoftheselectedexis ting Diagonal fractures occurred in significant parts of the in- 36
RCbuildings filled walls through the dissipation of energy. Therefore, no
significant damage was observed in load-bearing elements
The building used as case study 1 is located in the Simav (column,beam,etc.).Inaddition,theribbonwindowsofthe
district of Ku¨tahya Province. It comprises 5 stories: 1 base- basementstoryintherearfacadeofthebuildingcausedshear
ment, 1 ground story, 1 installation story, and 2 typical sto- cracks in upper bearings of columns (short column mecha-
ries. The building was constructed in 1990. The facade of nism).Figure11showstheappearanceofshortcolumnform-
the building is shown in Fig. 8. The load-bearing system of ing.
thebuildingwasplannedasareinforcedconcreteframe.The Unsupervisedconstructionandevendesignfactorsareim-
floor system of the building was beam slab with slab thick- portantcausesofdamageintherelevantbuilding(andother
ness of 12cm. In situ measurements of columns, which are governmentbuildingsinSimavdistrict)sustainedduringthe
the vertical bearing elements, determined that the columns earthquake. The examinations indicated frequent mistakes
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Fig. 11.

Fig. 12.

514 M.H.Arslanetal.: 19May2011Ku¨tahya
Fig. 11.
Fig. 11. Fig. 13.

Fig.11.Shear-columndamage.   Fig.13.Obtainedcoresamples. 37
Fig. 12.
Fig. 12.
building.Aftercompletingthegeneralgeometricalsurveyto
determinethecharacteristicsoftheas-builtproject,adetailed
experimental program was planned. This program includes
on-site destructive testing and laboratory tests on the speci-
mens(coremembers)obtainedfromthestructuralelements,
in order to evaluate the mechanical properties of concrete
materials (Fig. 13). The experiments were conducted in the
Earthquake and Construction Laboratory of Selcuk Univer-
sity. Average concrete compression resistance of the build-
ing was found to be 8.1MPa (f =81kgcm−2). The com-
c
pressivestrengthsofthecoremembersaregiveninTable5.
Observations made during the search-and-rescue phase and
core-removal works at the site suggested that the quality of
theconcreteusedwasextremelyinsufficient.Examinationof

theconcretecoresamplesobtainedfromthebuildingfound
Fig.12.Utilizedrebar(beamFF-ciioggl.u. m1133n..n odeofgroundstory). that the concrete aggregates had been used in their natural
states without being washed and sieved, and the grain size
distributionwasnotsuitableforahighqualityconcrete.
thatcannotbeexplainedwithprinciplesofRCconstruction. The class of steel rebar used in the building was S220
Thebasiccausesofdamagearedefectsintheplacementand (fy =220MPa).Therebarsintheloadsystemelementswere
themechanicalcharacteristicsoftransverseandlongitudinal locatedusingarebardetectiondevice;thenumberanddiam-
rebar, low concrete quality, inappropriate wall construction, etersofrebarsweredetermined,andaccuraterebardistribu-
andtheincreasedheightandlowrigidityofthegroundstory tion was recorded in the model. It was found that confine-
compared to other floors. The beam-column connection re- mentintervalsincolumnsandbeamswereabout17–25cm.
gion shown in Fig. 12 demonstrates that the building is far Theexaminationsdeterminedthatthevertical(longitudinal)
from complying with the provisions of TEC-2007. There is rebarratioincolumnswasapproximately0.8%–1.0%.
no stirrup in the column and beam connection region, stir- Soil core samples showed that the territorial soil class is
rups hooks have 90degree angles, there is hooking in the Z3,whichissimilartoclassCsoilinFEMA-356.TEC-2007
compression rebar, and the distance between rebars is non- specifiesspectrumcharacteristicperiodsas0.15sand0.60s
compliant. inthistypeofsoil.ThebuildingislocatedonQuaternaryold
alluvial,whichisclassifiedasclayeysand(SC;USCSclassi-

6.1.2 Seismicperformanceassessmentaccording ficationsystem).SPTnumberN30inthesoilgenerallyranges
  toTEC-2007 between7an3d730.Inafieldwherethedepthoftheground-
  37
waterlevelisbetween4.5and7.0m,topographicinclination
TheevaluationsaccordingtotheTEC-2007normsprimarily isabout0–5%.AccordingtoTEC-2007,inafieldwheresoil
determined on-site values of the load-bearing system of the classisCandterritorialsoilclassisZ3,groundwaterlevelis
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