Seismic landslide analysis: Gurpinar (Istanbul) as a case history

Slope failures triggered by earthquakes are among the most important soil mechanics problems. In this study, static and pseudostatic analyses of slope stability for earthquake conditions were carried out in the Gurpinar area. In situ testing (SPT) was carried out and laboratory samples were obtained from six boreholes (maximum depth 50.0 m) to determine soil classification and strength characteristics. Geophysical studies (seismic refraction and MASW) were also carried out in the area to estimate the structure and stiffness strength characteristics of the slope to 50.0 m depth. All field and laboratory data were used to determine the mechanical and structural (geometrical) behavior of the slope. In order to solve the slope stability problem, three soil slope models were considered. Pseudostatic analysis was carried out to estimate the earthquake acceleration seismic hazard in the region. These analyses showed that, while there was no potential slope instability under static load conditions, some problems would appear with increasing earthquake acceleration. A geotechnical slope improvement project is proposed for the study area.