Seismic performance of industrial facilities affected by the 1999 Turkey earthquake

transcript

Seismic Performance of Industrial Facilities Affectedby the 1999 Turkey Earthquake

Halil Sezen, M.ASCE1; and Andrew S. Whittaker, M.ASCE2

Abstract: Approximately 40% of the heavy industry in Turkey was located in the region affected by the 1999 Mw 7.4 Kocaeliearthquake. Twenty-four facilities representing different industries in the epicentral region were surveyed after the earthquake. Structuraland nonstructural damage to these facilities is summarized and performance is reported using a damage classification scheme. Informationon typical industrial-facility construction practice in Turkey is presented. Earthquake damage to the most common structural framingsystems is highlighted. The structural performance of a small number of the facilities visited by the reconnaissance team is investigated.

DOI: 10.1061/�ASCE�0887-3828�2006�20:1�28�

CE Database subject headings: Seismic effects; Industrial plants; Facilities; Turkey; Earthquakes; Damage.

Introduction

The Mw 7.4 earthquake that struck northwestern Turkey onAugust 17, 1999 caused extensive damage to residential,commercial, and industrial facilities. The majority of the affectedindustrial facilities were located a short distance from the NorthAnatolian fault that ruptured during the earthquake; see Fig. 1 fordetails. The geographic region that was impacted by the earth-quake was somewhat narrow-banded and stretched from Istanbulin the west to Golyaka in the east. In the days following theearthquake, 24 industrial facilities in the impacted region werevisited by a team representing the Pacific Earthquake EngineeringResearch �PEER� Center. The observed structural and nonstruc-tural damage to the visited facilities is reported in Sezen et al.�2000�.

The widespread damage to industrial facilities had a substan-tial impact on the economy of the region in terms of both directand indirect losses. Direct losses resulted from structural damageand nonstructural damage, and included damage to equipment,and mechanical, electrical, and plumbing systems. Indirect lossesaccrued from business interruption due to damage, loss of utili-ties, loss of transportation infrastructure, etc. To characterizedamage and likely loss, a performance scale for structural andnonstructural components was defined �Sezen et al. 2000�; thesescales are reported in Tables 1 and 2, respectively. A list of theindustrial facilities visited by the reconnaissance team, relevant

1Assistant Professor, Civil & Environmental Engineeringand Geodetic Science, The Ohio State Univ., 470 Hitchcock Hall, 2070Neil Ave., Columbus, OH 43210-1275 �corresponding author�. E-mail;sezen.l@osu.edu.

2Professor, Dept. of Civil, Structural and Environmental Engineering,230 Ketter Hall, Univ. at Buffalo, State Univ. of New York, Buffalo, NY14260.

Note. Discussion open until July 1, 2006. Separate discussions mustbe submitted for individual papers. To extend the closing date by onemonth, a written request must be filed with the ASCE Managing Editor.The manuscript for this paper was submitted for review and possiblepublication on August 3, 2004; approved on February 1, 2005. This paperis part of the Journal of Performance of Constructed Facilities, Vol. 20,No. 1, February 1, 2006. ©ASCE, ISSN 0887-3828/2006/1-28–36/

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construction information, and the approximate number of em-ployees in each facility are presented in Table 3. The degree ofdamage �and thus loss� suffered by each facility is also listed inTable 3. Additional information on the performance of industrialfacilities and other structures in the impacted region can be foundin Johnson et al. �2000�; Rahnama and Morrow �2000�; Sezenet al. �2000, 2003�; and Sezen and Whittaker �2004�.

This paper describes briefly the characteristics of the groundmotions recorded in the epicentral region and compares the elasticresponse spectra of these motions with modern building codedesign spectra. An overview of the most common structural sys-tems and typical construction practice for industrial facilities ispresented. The vulnerabilities of these structural systems and thecorresponding earthquake damage and performance are discussed.

Ground Motion Demands on Industrial Facilities

The industrial facilities visited by the reconnaissance team werelocated within approximately 50 km of the epicenter of the earth-quake. The circled numbers in Fig. 1 show the peak groundaccelerations at recording stations in the region affected by theearthquake: the maximum values varied between 0.2g and 0.4g.

Fig. 1. Map of affected region with industrial facilities relevant toepicenter �percentage of peak ground accelerations in terms of g areshown in circles�

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Most of the selected facilities discussed in this paper were locatednear Izmit �see Fig. 1� where the well-known Yarimca �YPT�earthquake histories were recorded. The horizontal �YPT-NS�North–South� and YPT-EW �East–West�� and vertical �YPT-UP�acceleration histories recorded at the YPT station are shown inFig. 2; the peak horizontal ground acceleration at the YPT stationwas 0.32g.

The seven strong motion stations that recorded groundmotions with peak accelerations larger than 0.14g are listed inTable 4. The closest distance to the fault rupture plane and siteclassifications are also listed in the table. Five-percent dampedelastic response spectra and the corresponding median spectrumfor the 13 horizontal acceleration histories from the seven record-ing stations are presented in Fig. 3�a�. The figure also presents theelastic design spectra calculated using the provisions of theTurkish Seismic Code �1998� and the 1997 Uniform buildingcode �UBC� �ICBO 1997� for rock and soft soil sites. The UBCspectra were constructed assuming a near-field amplification fac-tor of 1.0 and soil type SE �soft soil�. Fig. 3�a� can be used tocompare the spectral demands from the 13 recorded ground mo-tions with the elastic demands of the Turkish and U.S. buildingstandards in use at the time of the Kocaeli earthquake. Alsoshown in the figure is the median spectrum of the 13 horizontalcomponents of ground shaking identified in Table 4.

Two current specifications that can be used for the designof industrial facilities are the ASCE guidelines for seismicevaluation and design of petrochemical facilities �TaskCommittee 1997� and FEMA 368 “NEHRP recommended provi-sons for seismic regulations for new buildings and otherstructures” �FEMA 2001�. Fig. 3�b� presents the 5% dampedFEMA and ASCE elastic spectra and the median spectrum ofFig. 3�a�. Based on these data, the earthquake shaking recorded inthe epicentral region could be considered as representative ofdesign-basis shaking. The damage and performance observationsand calculations presented in the following sections should beviewed accordingly.

Table 2. Nonstructural Damage Classification

Level Damage Function

1 None Fully operational None

2 Minor Partially operational Clean up

3 Moderate Out of operation for days or several weeks Engineere

4 Major Out of operation for months Major rep

Table 1. Structural Damage Classification

Level Damage Function R

1 None Fully operational None

2 Minor Partially operational Mino

3 Moderate Out of operation fordays or several weeks

4 Major Out of operation for months Majorepla

5 Collapse None Not p

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Overview of Construction and Damage

In situ Reinforced Concrete Structures

In situ reinforced concrete moment-frame construction is com-mon in smaller and/or older industrial facilities in Turkey. Theconstruction quality in these facilities was, by-and-large, substan-tially better than that of residential and commercial reinforcedconcrete construction. Of the 24 industrial facilities visited by thePEER reconnaissance team, 14 were constructed with reinforcedconcrete moment-resisting frames. Most of the damaged in situconcrete structures were constructed without the use of moderndetails for ductile response, such as closely spaced transversereinforcement with 135° end-hooks.

Prefabricated Reinforced Concrete Structures

For reasons of economy and speed of construction, prefabricatedor precast reinforced concrete members were and still are com-monly used for the construction of new industrial facilities inTurkey. The typical span and height of these precast structuresvaries between 15 and 25 m, and 6 and 8 m, respectively. Threeof the most popular precast structural systems in Turkey areshown in Fig. 4. The frame of Fig. 4�a� is composed of individualcolumns and long-span rectangular or tapered beams, each with apinned support at one end and a sliding support at the other end.Lateral forces are resisted in these structures through cantileveraction of the precast concrete columns. The typical spacing ofthese frames was approximately 6 m. The pinned support wastypically composed of one or two anchorage dowels, which wereintended to prevent lateral movement but permitted rotation aboutan axis perpendicular to the plane of the frame. Reinforced con-crete planks spanned between the frames and were supported onpockets cast into the precast beams.

Typically, a precast column was inserted and grouted into adeep socket foundation to achieve fixity at its base. In general, the

r Typical damage

Negligible

Small movement of unanchored equipment; overturning ofcabinets and shelved products

ir Modest damage to architectural, mechanical, and plumbingsystems; failure of equipment anchorage and movement ofequipment

replacement Significant damage to nonstructural components

Typical damage

Negligible

Minor cracks in RC members; bolt failures in steel frames

ir Significant cracks in RC members; yielding in steel momentframes

r or Spalling and crushing of RC members; rebar fracturein RC members; fracture of steel components

Multiple component failures; part or full loss of floorsor roofs; gross distortion of steel frames; large permanentdrifts

d repa

air or

st repa

r repaicement

ossible

E OF CONSTRUCTED FACILITIES © ASCE / FEBRUARY 2006 / 29

Table 3. Industrial Facilities Visited by Reconnaissance Team

Facility Function/product Construction date Construction typea EmployeesStructuraldamageb

Nonstructuraldamagec

Adapazarisubstation

Powerdistribution

— RC NA 1 4

Bastas Fluorescent tubes 1960s RC NA 1 4

BekSA Steel cord 1987 RC 240 4 3

BriSA Tires 1974–1989 RC 100 4 3

Camlica Soft drinks 1999+ RC NA 4 3

Cap Textile Textiles 1997 RC 650 5 4

Citi Glass vials NA RC NA 3 3

DuSA Chemicals 1987 Assorted NA 4 4

DuSA Chemicals 1999+ Steel NA 1 NA

EnerjiSA Power 1997 Steel 50 2 3

Ford Automotive 1999+ RC NA 3 NA

Goodyear Tires 1963 Steel 500 2 3

Habas Liquid gases 1995 Assorted NA 5 4

Hyundai Automotive 1997 Steel 850 4 4

KordSA Tire cord 1973 Steel 1,100 3 3

Mannesmann Pipe 1955 Steel 200 3 3

Pakmaya Food processing 1976 Steel 300 4 4

Petkim Petrochemical 1967–1975 RC 2,500 5 3

Pirelli Tires 1962 RC 900 4 3

SEKA Paper mill 1936–1960 RC NA 4 4

Toprak Drug Drugs 1990 RC 240 2 4

Toprak Clean Cleaning supplies 1993 RC 250 3 4

Toyota Automotive 1994 Steel NA 1 2

Tupras Refinery 1961 Assorted 1,350 5 4aAssorted=steel and reinforced concrete; RC=reinforced concrete; NA=not available.bSee Table 1 for information on structural damage.cSee Table 2 for information on nonstructural damage.

Fig. 2. Horizontal and vertical acceleration records measured at Yarimca station

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sockets or foundations were joined to other footings by gradebeams and a thick slab at the top of the foundation. Typicalinterior and exterior foundation socket-column base details areshown in Fig. 5. Grade beams between exterior socket founda-tions can be seen in Fig. 5�a�. The column shown in Fig. 5�c�appears to have a sufficient amount of well-detailed transverseand longitudinal reinforcement, and a plastic hinge developednear its fixed base. The damage at the base of the column shownin Fig. 5�d� seems to be due in part to inadequate reinforcementdetailing. No damage to or rotation of any socket foundationswas observed, indicating that the socket foundations providesubstantial fixity at the base of the precast columns.

Typical prefabricated beam-column and plank constructionand damaged components are shown in Fig. 6. Fig. 6�a� shows theprefabricated beam/slab on the right-hand side of a damagedcolumn corbel that was close to collapse. Fig. 6�b� shows a fallenbeam: a collapse that resulted from corbel failure. In the epicen-tral region, a common prefabricated structural system includes aprecast T-shaped member at the top of the central column thatserves to connect the precast column to simply supported roofbeams �see Fig. 4�b��. Fig. 6�c� shows damage to a steel-pipeproduction facility, which was under construction at the time of

Fig. 3. �a� Elastic ground motion and design response spectra; and�b� elastic response spectra

the earthquake. The roof panels had not been installed at the time

of the earthquake, and as such, there was no diaphragm at the rooflevel. �The seismic load paths in this building, both parallel andperpendicular to the frames, would have been questionable evenif the roof panels had been installed.� As is evident in the figure,many of the columns acted as cantilevers and hinged at theirbases during the earthquake. The precast T-units of Fig. 6�c�rotated off the top of the two central columns in the middle of thephotograph and are upside down in the figure. There was minimalreinforcement joining the T-shaped units to the columns below.Many roof diaphragms in similar structures �one is shown inFig. 6�d�� were badly damaged or collapsed due to detailingknown to be inadequate by modern standards.

A third prefabricated framing system in use in Turkey at thetime of the earthquake is shown in Fig. 4�c�. The gravity-loadframing system in this figure is composed of a light steel �three-dimensional� space frame, which is supported by steel trusses thatspan between the precast reinforced concrete columns. Such con-struction was somewhat common in modern facilities constructedby joint ventures of Turkish and international companies, such asthe KordSA, BekSA, and Toprak Cleaning facilities. One suchfacility, the Ford assembly plant near Golcuk, was subjectedto ground failure and fault rupture within 100 m of the plant, andsuffered significant structural and nonstructural damage,including hinging at some column bases.

Steel-Frame Structures

Braced and moment-resisting steel frames are used for somesingle-story and many multistory industrial facilities. One suchfacility for DuSA �a joint venture between Dupont and Sabanci�was under construction at the time of the earthquake. The framingsystem in this five-story building suffered no damage but much ofthe reactive weight in the form of the concrete-on-metal deckfloors and masonry perimeter walls was not present at the timeof the earthquake. According to the contractor on site at the timeof the reconnaissance visit, the building was designed anddetailed in the United States using U.S. standards for such facili-ties. The seismic force-resisting system in this building includedmoment-resisting frames with bolted end-plate connections andeccentrically braced steel frames.

Performance of Selected Industrial Facilities

Tupras Refinery

Significant damage occurred at the Tupras oil refinery located

Table 4. Recorded Peak Ground Accelerations from Stations inEpicentral Region

StationDistancea

�km� Site class

Peak ground acceleration

N-S �%g� E-W �%g� Vertical �%

Duzce �DZC� 14 Soft soil 37 32 36

Sakarya �SKR� 3 Stiff soil NA 41 26

Izmit �IZT� 8 Rock 17 22 15

Yarimca �YPT� 4 Soft soil 32 23 24

Gebze �GBZ� 17 Stiff soil 26 14 20

Faith �FAT� 65 Soft soil 18 16 13

Ambarli �ATS� 79 Soft soil 25 18 8aDistance from rupture plane.

approximately 19 km from the epicenter and within 2.5 km of the

ruptured fault. Prior to the earthquake, the Tupras refineryproduced more than 200,000 barrels of oil-related product perday: approximately one-third of Turkey’s total output. The Tuprasrefinery was designed and constructed in the early 1960s byfollowing U.S. standards of practice at that time �ACI 1969;Sezen et al. 2000; Kilic and Sozen 2003�. As such, the types ofearthquake damage observed at the Tupras refinery would not beunexpected at refineries of a similar age located in other regionsof high seismicity around the world, including the west coast ofthe United States.

The damage to the Tupras refinery was widespread andincluded port facilities, storage tanks, cooling towers, stacks, andcrude-oil processing units. Much of the damage was fire related:an indirect consequence of the earthquake shaking. The fire-fighting capability of the refinery was lost immediately followingthe earthquake because of multiple ruptures of the water pipelinefrom Lake Sapanca, 45 km to the east of the refinery. The refineryreceived all of its water from this lake. In the days immediatelyfollowing the earthquake, the resulting fires were contained byaerial bombardment with foam. At the height of the conflagration,a 3-km region around the refinery was evacuated. The fires wereextinguished by water drawn from Izmit Bay using portable diesel

Fig. 4. Prefabricated construction including reinforced co

pumps and flexible hose that did not arrive at the refinery until

3 days after the earthquake. Had this fire-fighting equipment beenstockpiled at the refinery in advance of the earthquake, the firesthat took 5 days to extinguish would have been put out muchsooner. Valuable lessons for refineries on the west coast of theUnited States can be learned from the problems encountered bythe fire-fighting and emergency-response teams at the Tuprasrefinery.

Many of the 100+ tanks in the Tupras refinery farm wereconstructed with floating roofs. Similar to observations from otherearthquakes �Task Committee 1997�, sloshing of the fluid in manyof these tanks damaged the perimeter seal, which permitted thefluid to escape from the containment. Substantial damage to alarge number of tanks �30+ � in the Tupras tank farm wasreported. The inability of perimeter seals to retain the sloshingfluid in the tanks resulted in the failure or sinking of these floatingroofs. Each of these damaged floating roofs required repair orreplacement before the tanks could be returned to service. Repairof the damaged or sunken roofs involved draining the tanks,decontamination of the roof, and replacement of the perimeterseals.

None of the tanks visited by the reconnaissance team wereanchored to their foundations but there was no evidence of sub-

columns with prefabricated beams and steel-truss beams

stantial sliding of the tanks. Although hard piping was attached at

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the base of each tank, there was no evidence of pipe failure in anyof the tanks not consumed by fire. Approximately 20 tanks in theTupras tank farm were severely damaged or destroyed by fire�Fig. 7�a��. Gross expansion of one fixed-roof tank due to intenseheating is shown in Fig. 7�b�.

The main processing facility at Tupras is composed of threecrude-oil processing units. One of the three units, which was con-structed in 1983, was destroyed by the collapse of a 115-m-tallreinforced concrete heater stack in the middle of the unit�Fig. 7�c��. The upper two-thirds of one of the heater stacks�Stack 25F-5, in the middle in Fig. 7�c�� collapsed whereas asimilar stack �Stack 36F-5� survived. Both stacks were designedand detailed in 1978 following the requirements of ACI 307�ACI 1969�. The stacks had large penetrations for ductwork lo-cated approximately 30 m above their bases. Kilic and Sozen�2003� analyzed the two stacks and concluded that the collapse ofthe 25F-5 stack was not due to a lack of strength or materialdeficiencies, but due to brittle failure of the reinforcing-barsplices in the region where flexural yielding occurred, near thepenetration. The other stack had two smaller penetrations at thesame height but suffered no apparent damage. Using the groundmotions recorded at the YPT station, which was located within2 km of the stacks, and the estimated modal periods of the stacks,Kilic and Sozen compared flexural demand and resistances alongthe height of the two stacks and concluded that the flexural yield-ing was likely to occur at the base of Stack 36F-5 whereas thecritical section was at the penetration of Stack 25F-5. Fig. 7�d�

Fig. 5. �a� Exterior socket foundations with grade beams; �b� interiorcolumns with socket foundations; �c� plastic hinging; and �d� damageat the end of a column with socket foundation �photo in �d� fromSaatcioglu et al. 2001, with permission�

�from Kilic and Sozen 2003� shows the variation of flexural

resistances along the heights of Stacks 36F-5 and 25F-5. Some ofthe pipework was fractured by the collapsing Stack 25F-5, whichignited fires in the crude-oil unit. These fires caused structuralsteel components that supported the furnace and the pipe runwaysto buckle and fail �Sezen et al. 2000�.

Sliding Tanks and Transformers

Cylindrical liquid gas tanks of the type shown in Fig. 8 werecommon in the industrial facilities in the region affected by the1999 Kocaeli earthquake. These tanks were supported by eithershort/rigid reinforced concrete piers/pedestals or tall flexible steelpiers. Most of the tanks viewed by the reconnaissance team, thatwere similar to that seen in Fig. 8, were not anchored and hadhard pipe connections to supporting infrastructure. These connec-tions were susceptible to damage due to the lateral movement androtation of the tank with respect to the supporting saddle. Move-ment and rotation of the tank with respect to the pedestal areclearly evident in Fig. 8.

The EnerjiSA power generation facility in Izmit sustainedsome damage to its electricity and steam generation equipmentduring the earthquake. Transformers in the EnerjiSA facility weremounted on rails to facilitate installation and maintenance. Simplebraking mechanisms were used to prevent movement of thetransformers such as bushings. Movement along the rails of eachtransformer in the EnerjiSA transformer yard was observed. Thetypical movement, ranging between 50 and 100 mm, was mostlikely too small to endanger the interconnected equipment such asbushings. However, one of the rail-mounted transformers, whichwas not in service at the time of the earthquake, rolled or slidmore than 1 m, dropped off the ends of the two support rails, andoverturned as shown in Fig. 9. Improved anchorage details wouldhave prevented movement and damage of the transformer.

Elevated Tanks and Performance Evaluation

The Habas plant, located within 10 km of the fault trace near the

Fig. 6. Damage to typical prefabricated construction: �a,b� damagedconnections; �c� failed central columns and T-shaped units; and �d�damaged roof

city of Izmit, provides liquefied gases to commercial plants and

medical facilities in the affected region. The major damage atHabas was the collapse of two of the three liquid gas storagetanks shown in Fig. 10. Three identical 14.6-m-diameter tankswere built in 1995. Each storage tank consisted of two concentricstainless steel tanks, one with an outside diameter of 14.6 m andthe other with an outside diameter of 12.8 m. The gap betweenthe tanks was filled with insulation. Both tanks were supported ona 14.6-m-diameter, 1.07-m-thick reinforced concrete slab that wasin turn supported by 16 200-mm-diameter reinforced concretecolumns. Each column was 2.5 m in height and reinforced with16 16-mm-diameter longitudinal bars and 8-mm-diameter ties at100 mm on center: data gleaned from review of the failed tank-support columns.

The two tanks containing liquid oxygen collapsed as seen inFig. 10. The tank and supporting structure containing liquidnitrogen were undamaged except for some hairline cracks in thecolumns. Habas representatives on site during the reconnaissancevisit reported that the liquid oxygen tanks were 85% full and theliquid nitrogen tank was 25% full immediately prior to the earth-quake. Photographs of some of the failed columns beneath one ofthe liquid nitrogen tanks are shown in Fig. 10.

Fig. 9. Toppled transformer in the EnerjiSA facility

Fig. 10. Liquid oxygen and nitrogen tanks at the Habas

Fig. 7. �a� Tanks destroyed by fire; �b� gross expansion of fixed rooftank; �c� damage to heater stacks at the Tupras refinery; and �d�calculated capacities of heater stacks �Kilic and Sozen 2003�

Fig. 8. Cylindrical liquid gas tank

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To better judge the strength of the columns supporting thetanks, sample design calculations for a new tank of the samedimensions as the Habas tanks were prepared. Fig. 11 presents adiscretized column cross section, axial load-moment interactioncurve, and the lateral load-flexural displacement relations for atypical support column. Flexural displacements were obtained byintegrating the cross-sectional curvatures along the length of thecolumn. For the interaction curve and moment-curvature calcula-

Fig. 11. �a� Fiber cross-section model; �b� axial load-momentinteraction diagram; and �c� flexural behavior of circular columns atthe Habas facility

tions, an estimated concrete compressive strength, fc�, of 28 MPa

and a confined concrete strength of 35 MPa �per Manderet al. 1988� were used. The yield and tensile strengths of thelongitudinal steel were estimated to be 414 and 620 MPa,respectively. Fig. 11�b� shows the calculated axial load-momentinteraction diagram without capacity reduction factors. The axialloads highlighted in the figure are the unfactored gravity load forthe 85% full liquid oxygen tank �P=4,533 kN�, and theunfactored gravity load for the 25% full liquid nitrogen tank�P=1,237 kN�. The column axial load at balanced condition isapproximately 1,950 kN. Since the 4,533-kN-axial load is largerthan the balanced axial load, it is expected that the column wouldfail in a brittle manner by concrete crushing before longitudinalreinforcement yielding. For the 85% full liquid oxygen tanks, thisobservation is supported by the observed brittle column failurewith no sign of flexural yielding �Fig. 10�. As shown in Fig. 11,the maximum moment, Mp, corresponding to the unfactoredgravity load of 4,533 kN is 369 kN m. Assuming fixity at the topand bottom of the column and ignoring changes in axial force dueto global overturning moments, the corresponding shear force is291 kN or 6.4% of the supported weight. Assuming that the liquidoxygen tank was 85% full and that the fluid was 100% reactive,the peak ground acceleration required to fail the columns is0.064g. Because the fluid in the 85% full oxygen tanks was freeto slosh and not 100% reactive, the intensity of shaking requiredto fail the partially empty liquid oxygen tank would likely haveexceeded 0.064g. Considering that the recorded peak groundaccelerations in the area �Table 3� were typically much larger than0.064g, the column failures and the resulting collapse of the tanksare not unexpected. At the unfactored gravity load of 1,237 kN,the maximum coexisting moment is 441 kN m. For a column withfixed end supports, this corresponds to a shear force of 347 kN or28% of the supported weight. The peak ground acceleration re-quired to fail the columns carrying 25% full liquid nitrogen tanksis 0.28g.

The column lateral load-flexure displacement relations, shownin Fig. 11�c� for different levels of axial load, indicate that thedisplacement capacity decreases with increasing axial load. Forthe axial load of 4,533 kN, the maximum flexural displacementprior to strength degradation is approximately 13 mm. The dis-placement capacity of such columns is extremely small. The de-formation capacity �prior to strength degradation� of the columnssupporting the substantially empty liquid nitrogen tank wasgreater than that of the columns supporting the liquid oxygentanks. Thus, although the strengths of these columns were similar,the displacement capacity of the columns supporting the liquidnitrogen tank was greater than that of the columns supporting theliquid oxygen tanks.

Conclusions

As a result of field investigations of 24 industrial facilitiesfollowing the 1999 Kocaeli, Turkey earthquake, a scale wasdeveloped for classifying the performance of structural and non-structural damage. The characteristics of the ground motionsrecorded in the epicentral region are reported and compared withthe design-basis earthquake elastic demands on buildingstructures. The recorded ground motion histories are consistentwith those expected in design-basis earthquakes. An overview ofin situ reinforced concrete, prefabricated and precast concrete,and steel structural systems used in the earthquake affected area ispresented. Some of these systems had structural deficiencies, and

evaluation of selected industrial facilities in the epicentral regionshowed that damage would have been expected in design-basisearthquake shaking.

Acknowledgments

This work was supported by the Pacific Earthquake EngineeringResearch �PEER� Center through the Earthquake EngineeringResearch Centers Program of the National Science Foundationunder Award Number EEC-9701568. This support is gratefullyacknowledged. The writers would like to acknowledge the othermembers of the PEER reconnaissance team including ProfessorsKen Elwood, Khalid Mosalam, John Wallace, and John Stanton.The writers also acknowledge the cooperation, assistance, andaccess provided by the management and staff at the affected in-dustrial facilities visited by the reconnaissance team.

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Seismic performance of industrial facilities affected by the 1999 Turkey earthquake

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