Numerous prior studies indicate that the topography of the ground surface as well as underground layering of soils (stratigraphy) can significantly affect the seismic input to structures. In this study, we provide preliminary results from an ongoing study—funded by The Scientific and Technological Research Council of Turkey, TUBITAK—examining and quantifying the topography-induced changes in seismic motions experienced by surface infrastructure located within a region of Istanbul. The goal is to transform SSI analyses to consider realistic site conditions. An important part of this effort involves the creation of a map of topography-induced SSI response amplification factors for the south European side of Istanbul by performing extremely large 3D simulations using real site topography and soil stratigraphy data, and realistic bedrock ground motions, which are available from previously completed earthquake scenario and seismic microzonation studies.

1. W. Zhang, A. Kurtulus, D. Restrepo, R. Taborda, A. Ansal, E. Taciroglu (2019), An investigation of the effects of surface topography on the seismic structural demands for a region of Istanbul, Seventh International Conference on Earthquake Geotechnical Engineering (7ICEGE), Roma, Italy, June 17-20

2. W. Zhang, E. Esmaeilzadeh Seylabi, E. Taciroglu (2017), Effects of soil stratigraphy on dynamic soil-structure interaction behavior of large underground structures, 3rd International Conference on Performance-based Design in Earthquake Geotechnical Engineering (PBD-III), Vancouver, Canada, July 16-19