Investigation of local side effects with one and two dimensional analyses

Geological and geotechnical features of Zeytinburnu District with 11.16 km2 residential area has been studied by Yildiz Technical University Deparment of Civil Engineering/Geotechnics Division (Ozaydın et al.,2004) during the seismic microzonation study, which was part of the ?Istanbul Earthquake Master Plan, Zeytinburnu Pilot Project?. In this thesis, one and two dimensional dynamic behaviour analyses are made on three cross-sections in the district by using the data obtained from this project to evaluate the expected surface ground movements during the earthquakes. Thus the effect of local topography and soil conditions could be examined and the comparison between one and two dimensional dynamic analyses results could be performed.One dimensional analyses are made with both the program EERA which is utilizes an equivalent linear analysis method and the program Deepsoil which can both run equivalent linear and nonlinear analyses. For two dimensional analyses Plaxis 8.5 dynamic pack is used. Viscous damping parameters used in the Plaxis 8.5 dynamic analyses are obtained from the Deepsoil analysis. In dynamic analyses, synthetic acceleration records representing possible İstanbul earthquake for 475 years return period are used as bedrock input motion. Analyses are repeated for the purpose of examining the effect of topography and layer boundaries for one of the sections with boundaries being modelled as horizontal.The analyses results showed that the properties of surface ground motion differs according to the land topography and local soil conditions.Peak ground acceleration and maximum spectral acceleration values derived from 1D and 2D analyses are compared with each other considering the changes in the topography.Key Words: Zeytinburnu, dynamic behaviour analyses, Plaxis, EERA, Deepsoil