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SHEAR WAVE VELOCITY PROFILING BY SASW METHOD AT SELECTED STRONG-MOTION STATIONS, LIQUEFACTION SITES, AND SITES OF BUILDING DAMAGE: 1999 TURKEY EARTHQUAKE

COLLABORATORS:
     - Dr. Brent Rosenblad (Univ. of Missouri, formerly at Univ. of Texas)
     - Prof. Kenneth Stokoe (PI)
     - Prof. Mustafa Erdik (Kandilli Observatory and Earthquake Research Institute)
     - Mr. Cem Ozbey (Kandilli Observatory and Earthquake Research Institute)
     - Dr. Ugur Kuran (General Directorate of Disaster Affairs)
     - Mr. Halit Kaya (Kaya Engineering)

FUNDED BY: National Science Foundation and PEER Lifelines Program.

DATA REPORTS
- Shear Wave Velocity Profiling by the SASW Method at Selected Strong-Motion Stations in Turkey by Rosenblad, Rathje and Stokoe, University of Texas at Austin
- Appendix A - All SASW Test Data
- Appendix B - Photographs of Test Sites

DESCRIPTION
The 1999 Kocaeli and Duzce earthquakes in Turkey have generated important information and data at stations where strong ground motions were recorded and sites where significant soil liquefaction occurred. One key variable in investigating the earthquake response at these sites is the shear stiffness profile of the subsurface soils. Researchers at the University of Texas at Austin (UT) conducted a joint study with Utah State University (USU) to characterize small-strain shear wave velocity profiles at selected sites using in situ seismic measurements. UT personnel were responsible for determining shear wave velocity profiles at 20 strong motion stations. These evaluations were performed using the spectral-analysis-of-surface-waves (SASW) method and extended to depths between 6 and 45 m, depending on spatial and source considerations.

Twenty strong-motion stations were tested as part of this study. Testing focused mainly on near-fault stations, typically within 30 km from the fault. The near-fault stations tested from the Izmit earthquake are Sakarya (SKR, 3.3 km), Yarimca (YPT, 4.4 km), Izmit (IZT, 5 km), Duzce (DZC, 12.5 km), Gebze (GBZ, 13.5 km), Arcelik (ARC, 21.6 km), and Iznik (IZN, 29.7 km). Two sites in western Istanbul (Ambarli [ATS, 78.9 km] and Cekmece [CNA, 76.1 km]) were also tested because of the unusually large ground motions recorded at these strong-motion stations from the Izmit earthquake (EERI 2000). The near-fault stations tested from the Duzce earthquake are Bolu (BOL, 17.6 km) and 6 temporary recording stations installed by the Lamont-Dougherty (LD) Observatory of Columbia University. The LD stations tested are LD-7 (1 km), LD-5 (11.4 km), LD-12 (13.3 km), LD-10 (15.6 km), LD-3 (27.4 km), and LD-9 (30.2 km). These stations are all located west of the Duzce earthquake fault rupture. Additionally, two aftershock stations in the Duzce alluvial valley (Ballica and Aydipinar) and two aftershock stations in Yalova (Hastane and Hilal), all installed by the Kandilli Observatory and Earthquake Research Institute, were tested. The report describing all testing results can be found below, as well as photographs from the field testing.

PUBLICATIONS
Rathje, E.M., Stokoe, K.H., and Rosenblad, B.L. 2003. “Strong Motion Station Characterization and Site Effects During the 1999 Earthquakes in Turkey,” Earthquake Spectra, Earthquake Engineering Research Institute, 19(3), pp. 653-676.

Rathje, E.M., Rosenblad, B.L., Stokoe, K.H., and Darendeli, M. 2002. “Shear Wave Velocity Profiling by SASW Method at Selected Strong-Motion Stations from the 1999 Turkey Earthquakes,” Proceedings, NSF-Tubitak Workshop on Turkey and Taiwan Earthquake Research, Antalya, Turkey, March.

Rathje, E.M. 2001. “Processing of Strong Motion Data from the 1999 Kocaeli and Duzce Earthquakes,” Final Report to Pacific Earthquake Engineering Center, November, 11 pp.

Rosenblad, B.L., Rathje, E.M., and Stokoe, K.H. 2001. “Shear Wave Velocity Profiling by SASW Method at Selected Strong-Motion Stations from the 1999 Turkey Earthquakes,” Final Report to Pacific Earthquake Engineering Research Center, September.

Rathje, E. Idriss, I.M., and Somerville, P., 2000. “Strong Ground Motions and Site Effects,” in Earthquake Spectra, The 1999 Kocaeli, Turkey, Earthquake Reconnaissance Report, Earthquake Engineering Research Institute, 16(A), pp. 65-96.

Photographs from Field Testing (Click on picture to enlarge)

Bulldozer surface wave source (Arcelik strong motion station)	Drop weight source (Hilal aftershock  station)
Hammer source (Aydipinar aftershock station)	Dr. Ken Stokoe with SASW electronic equipment and Turkish Tea
Dr. Ellen Rathje paying for services rendered	The beautiful view from the LD5 strong motion station
The field testing personnel with our bulldozer in Ballica (Top- bulldozer operator and Ellen Rathje; Bottom - Ken Stokoe, Ballica resident, Ugur Kuran, Halit Kaya, and the Captain; taking picture - Brent Rosenblad)	The field testing team at the end of the trip (Ellen Rathje, Halit Kaya, Ugur Kuran, Brent Rosenblad, the Captain, and Cem Ozbey)