EERI SPECIAL EARTHQU:A.KE REPORT -SEPTEMBER 1998

being in the fourth zone by the cur- rent Seismic Zoning Map (1996).

Strong Motion Records

According to the Ministry of Recon- struction and Resettlement, only a single strong-motion main shock record was obtained in the area. This record from had peak accelerations of 0.22 g (NS), 0.28 g (EW) and 0.086 g (UP). The rec- ords show several dominant fre- quencies (periods) at approxi- mately 0.7, 1 and 1.5 Hz (1.4, 1 and .67 sec). These resonating fre- quencies are within the site fre- quencies that can be expected from Figure 2 -Map showing the epicenter of the earthquake and the seismic alluvial media with depths ranging network operated by Marmara Research Center (www.nemrut.mam.gov.tr) from 25-75 m. It is possible that double resonance was one of the face in the valley is, in general, ond Seismic Zone, according to the main causes of collapses or severe loose gravelly or dense hard allu- Seismic Zoning Map of . damage in the mid-rise buildings in vium mixed with pockets of sand (There are five zones, with Zone 1 Ceyhan. Soil-structure interaction and clay-sand. In the northern part and Zone 2 assigned seismic coef- of(reinforced the rather concrete stiff buildings frame with ma- , of the dominant geological ficients of 0.4 and 0.3, respectively, formation is hard conglomerate. according to the new Seismic De- sonry infill walls) may have contrib- sign Code of Turkey, 1997. ) One uted to lengthening of the buildings' To the west of the epicentral re- of the main concerns of the region periods to coincide with the domi- gion, there are two small mountains in the last 25 years has been the nant periods of the site. The re- (elevation 763m). The Ceyhan planning of a medium-size nuclear sponse spectra demonstrate that River meanders to the east of these power plant in Akkuyu approxi- the horizontal components of mo- mountains. The Misis-Ceyhan Fault mately 100 km east of the tion had several dominant peaks follows the general NNE direction epicenter). The site is identified as within a 0.2-0.7 second band. of the two mountains (Barka, 1998). Below this, the young alluvial layers consist of gravels, sand and clay layers. Underground water can be located at one to three meters depth in young layers and at six to eight meters in older layers. Par- ticularly in the epicentral area, there was considerable liquefaction (see Figure 3). The water table in this area is considered to be within one to three meters of the surface.

The region is known to be seismi- cally active, but because of the short length of the faults in the area, large earthquakes (with mag- nitudes greater than 7) are not his- toriCally known or expected. The historical database refers to several damaging earthquakes with magni- tudes less than 7.

Adana and Ceyhan are in the Sec- Figure 3 -Sand boils due to liquefaction in a field near the epicenter. Photo: C;:elebi

.., EERI SPECIAL EARTHQUAKE REPORT -SEPTEMBER 1998 A JUNE 27.1 ggeI13:56GMT] ADANA EQ.-MAIN SHOCI<-STATION:CEYHAN Building Inventory

Typical building construction in the 011 area is reinforced concrete framed CI building with (cinder block or hol- : 0.2 w low-brick) infill walls. Often, the C C (1 slabs are also of cinder-block type. < There are many older, timber- -0.2 reinforced adobe, stone or brick masonry buildings. Some of the older structures in the older pari of 0 5 10 15 20 25 Adana or in the villages are of TIME (5J block stone masonry .Most of the RE5PON5E5PECTRA industrial plants significant to the 1 III 111111 III 111111 III 111111 III 1111]

economy of the area are of a \ 0:. prestressed and precast concrete u : : ; E;W ~ C ~ts ! ..: : u construction. Steel construction is < ,.: : .:;..;.:.:.;;.;;.;:..:.:;. :: : : : : : f:':- ' ' .: '~ : .:;.: :...:..:.;.:.~~: : : : : : : :;...:..:..;.;:.;; -' practically non-existent.

O 2i ; ; ; :" .; ; ;

...;.-i K ; ; ; Types of Damage ; 0.~2: :: : : ..: : ~ ... IO.~1 :0.067: : : : : : :

The causes of damage can be at- 0 tributed to one or a combination of 10-2 10-1 loa 101 102 the following: (a) soft first story I PERIO[) (5J

, now an in,ernationally known defect Figure 4- Strong-motion records from the Ceyhan Station (on ground f/oor

Oin desi~n, (b) inadequate detailing of three-story building) and corresponding response spectra. i and reinforcements of column- beam connections and columns Mahallesi). Two buildings-Ugur gle-story, stone masonry building (insufficient or lack of shear rein- Apartmenta and Basher Apart- on Ismet Inonu Boulevard, was not forcement, anchorages, inadequate ments-caused a total of 57 damaged; however, many of the spacing of ties, inadequate bonding deaths. Older buildings in Tuzlugol seven to eight-story buildings of round bars used instead of de- subdivision, apparently an old river across from the train station were. formed bars), (c) design of strong bed, also suffered, but these were As mentioned before, there is a beam/weak columns rather than mainly one to two-story buildings strong possibility that damage to strong-column/weak beams, (d) built on irrigated or formerly irri- mid-rise buildings in Ceyhan was creation of short-columns due to gated agricultural areas. The Cey- enhanced by double resonance infill walls or offsets in design, (e) han Train Station, a very stiff, sin- and/or soil-structure interaction. unreinforced or inadequately reIn- forced concrete and/or brick ma- sonry piers or coupling beams, (f) age of deteriorated buildings with little lateral load resistance, (g) questionable quality of materials used (concrete, steel, mortar, brick, cinder block, river washed stone- masonry), (h) site effects, double- resonance and soil-structure inter- action of the five to ten-story build- ings on alluvial media with single ; story basements and no piles.

J'\Structures in Ceyhan: Ceyhan V suffered the most damage and loss of lives. Most of the damages and deaths occurred in only a few of the seven to ten-story apartment build- I ings located in two subdivisions

(Konakoglu Mahallesi, Cumhuriyet Figure 5 -Ceyhan: unoccupied new eight-story structure pancaked. Photo: Celebi EERI SPECIAL EARTHQUAKE REPORT-SEPTEMBER 1998

Bridges and Lifelines: None of period following the earthquake. the bridges on the Ceyhan River in Adana was damaged, but the his- The extent of damage to the mid- torical Misis bridge in Misis (at the rise buildings, particularly in Cey- epicentral area) was partially dam- han, caused extensive concern aged (see Figure 8). All bridges on about the fact that there is no li- the Ceyhan River in Adana were censing requirement for contrac- intact. There were only minor dam- tors. It was determined that a sig- ages to the overpass bridges along nificant number of the "contractors" the Cukurova Toll Autobahn. were not trained. Those who are capable of financing a construction Industrial Facilities: Although the project are able to have a construc- industrial facilities in Adana ap- tion contracting business. Within peared not to be damaged from ten days of the earthquake. six un- outside, the news media reported qualified contractors were arrested that there was significant contents for their faulty construction that damage in some of the plants. caused loss of lives and property. There were calls for strict licensing Social and Legal Issues processes for contractors, and de- mands for better construction con- trol by municipal and government Adana is the fourth largest city in engineers. Turkey, and the whole Cukurova Basin is a major industrial and agri- Figure 6 -Deficient shear rein- Good Performance from cultural region with significant con- forcement at top end of column at tribution to the Turkish economy. Many Structures 9ukurova University. Photo: <;:elebi The population in the region was 0 caught completely off-guard when In both Adana and Ceyhan there Structures in Adana: In general, the earthquake occurred. Most peo- were many buildings that per- most of the new mid-rise and tall ple in the region probably had not formed well. The well-designed buildings in Adana (5-15 stories) experienced such a strong shaking and numerous shear walls present performed well. It is possible that before. Some families moved to certainly contributed to the satisfac- the characteristics and the peak ac- the higher in the tory performance of buildings dur- celeration of ground motions in Adana were not as severe as in Ceyhan due to different soil-depth and site response characteristics. It appeared that the quality of con- struction practices in Adana was better than in Ceyhan. The build- ings damaged and/or collapsed in Adana were older and shorter.

The Cukurova University Medical Facility Hospital Building was seri- ously damaged. This large complex was shut down immediately after the earthquake, but was reopened within 48 hours following inspec- tions by a group of engineers. There were separation of intill walls from the frame, X-cracks of infill walls, some column damage due to insufficient ties and some due to short-column effect (see Figure 6). Reserve strength in the walls and! or frames with infill walls must have contributed to saving the integrity of Figure 7- Separation of infill walls at the 9ukurova University Medical Facil- the hospital building (see Figure 7). ity Hospital Building. Photo:yelebi

4 EERI SPECIAL EARTHQUAKE REPORT- SEPTEMBER 1998

ing this earthquake. The infill walls by the Ministry of Public Works and More photos from Ceyhan-Adana may have contributed positively by Resettlement, Ankara, Turkey. are on the EERI web page. See adding to the requisite reserve them at: http:/Iwww.eeri.org strength and stiffness of the rein- forced concrete frame buildings (refer to the discussion of the C;u- kurova University Hospital Build- ing).

Approximately ten miles east of Adana is the Incirlik Air Force Base. A significant number of buildings here suffered damage, but none collapsed. Much of the damage re- sulted from fallen false ceilings in the base shopping unit.

Acknowledgements

The suppor1 from EERI's Learning from Ear1hquakes project-funded by the National Science Founda- tion-is gratefully acknowledged. The writer thanks Mr. Stuar1 Jones, ' American Consul General in Adana { and Professor Can Ozsahinoglu " ) (Rector of Cukurova University),

Professor Orhan Aksogan (Civil En- Figure 8 -Historical Misis bridge in the epicentral area. Photo: gelebi gineering Faculty at Cukurova Uni- versity), and Professor Serpil On- der (Pharmaceutical Faculty at Cu- kurova University) for all their help. Mr. Mehmet Ozdemir at Tarsus American College-my Alma Ma- ter-made it possible for me to post digital photographs of the ear1h- quake by using the e-mail facilities at the college.

References

Barka, A. and Akyuz, S., 1998, "Oeprem yerinden gozlem- ler" (Observations from earthquake region), Cumhuriyet Newspaper, July 9.

The Seismic Zoning Map of Tur- key (Turkiye Deprem Bolgeleri Haritasi), 1996. Enacted on 18 April 1996 and published by the Ministry rot Public Works and Resettlement, Ankara, Turkey.

Design Provisions for Structures in Seismic Zones (Deprem Bol- gelerinde Yapilacak Yapilar Hak- Figure 9 -Soft first story of new construction resulted in cracks in columns. kjnda Yonetmelik) , 1997. Published Photo: yelebi

5 EERI SPECIAL EARTHQUAKE REPORT -SEPTEMBER 1998

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