Project Objectives:  Significant occurrences of ground failure in the form of liquefaction, ground softening, and lateral spreading were documented by NSF-sponsored reconnaissance teams in several areas affected by the 1999 Kocaeli earthquake (M_w = 7.4).  The primary goal of this project is to characterize the subsurface conditions at sites where ground deformations and/or building movements were well documented.  Site characterization is being completed through the use of the cone penetration testing (some with pore pressure and shear wave velocity measurements) and rotary wash borings with primarily standard penetration testing (with energy measurements with the SPT Analyzer).  The project is divided into 4 phases as shown below, with emphasis given to developing the data necessary to analyze the relationship between ground failure and building damage, to assess the threshold for liquefaction triggering for soils with significant fines (both non-plastic and plastic), and to document ground conditions and displacements at several sites of minor and significant lateral spreading.  The data being collected through this research is being made available through this website as soon as possible to support the efforts of other investigators interested in these problems.
 

Project Benefits for California:  The goal of California’s Seismic Hazards Mapping Act is "to protect public safety from the effects of strong ground shaking, liquefaction, landslides, or other ground failure, and other hazards caused by earthquakes" (CDMG SP-117, 1997).  The seismic hazards mapping effort is largely based on empirical methods that require re-evaluation and updating as important case histories emerge.  Critical lessons can be learned from studying ground failure during the Turkey earthquake, because the soils and earthquake shaking represent one of the controlling earthquake hazards in California (i.e. poor soils close to large magnitude earthquakes).  Ground failure incidents were widespread in Turkey, where hundreds of structures settled, tilted and collapsed due in part to liquefaction and ground softening.  There were also observations of ground failure that have not been documented previously, such as horizontal translation of building founded on softened ground.  An in-depth examination of these cases is required to ensure the profession is not ignoring an important earthquake hazard.  Observations from design level earthquakes are invaluable to advancing the state-of-practice in earthquake engineering, and observations of ground failure in Turkey are transferable to California.

Phase 1	Phase 2	Phase 3	Phase 4
Ground Failure and Building Performance in Adapazari, Turkey Jonathan D. Bray, University of California, Berkeley with A. Önalp of Sa. U., H. T. Durgunoglu of ZETAS, & J. Stewart of UCLA	CPT Liquefaction Investigations, Adapazari, Turkey T. Leslie Youd, Brigham Young University with J. D. Bray of UCB, A. Önalp of Sa. U., H. T. Durgunoglu of ZETAS, & J. Stewart of UCLA	Geotechnical Site Investigation at Electrical Sub-Stations Jonathan D. Bray, University of California, Berkeley with H. T. Durgunoglu of ZETAS, A. Önalp of Sa. U., & R. Seed of UCB	Geotechnical Site Investigation at Lateral Spread Sites T. Leslie Youd, Brigham Young University, & K. Ö. Çetin of METU with J. D. Bray and R. Seed of UCB, H. T. Durgunoglu of ZETAS & A. Önalp of Sa. U.
Project Description	Project Description	Project Description	Project Description
Data & Site Location	Data & Site Location	Data & Site Location	Data & Site Location
Additional Information:  This is an ongoing research project, so this website will be updated periodically as more information becomes available.  Please contact the website manager, Mr. Rodolfo B. Sancio, if you have any questions regarding the data presented on this website.
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