Nonlinear Site Response Analysis for the Izmir Region: A Case Study

Abstract

Izmir city is mostly located on deep alluvial sediments capable of amplifying ground motions during an earthquake.  Soil layers composed of sand with a high groundwater table are very common in these regions. The three areas of Karşıyaka, Mavişehir and Bornova in Izmir city are seen as particularly interesting due to the large amounts of alluvial fan, plain and delta deposits expected in these areas. Site effects should be considered when specifying ground shaking levels for seismic designs to prevent earthquake damages. One-dimensional site response analysis is widely used to quantify the effects of soil deposits on propagated ground motions in research and practice. In this study, one-dimensional ground response analyses for a specific site which is known as liquefiable site in Izmir were performed with using a nonlinear method based on effective stress modelling in time domain. In order to estimate the ground response of liquefiable site, DEEPSOIL software which is a one-dimensional site response analysis program was used. Results of the two original sites under two different earthquake motions are given in terms of peak ground accelerations (PGA) and spectral accelerations.

Keywords

• Site response,liquefaction,DEEPSOIL,nonlinear analysis,earthquake

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