Gözlenen deprem hızlanma kayıtlarına göre 1D ve 2D site müdahale analizleri arasında karşılaştırma çalışması

Dynamic site response analysis is a technique that uses site characteristics and dynamic movements to attempt to predict the response of the specific site to ground motions in the form of response spectra. The main objective of the present work is to evaluate the difference between the one-dimensional and two-dimensional site response analysis, based on the comparison among the peak ground and spectral accelerations recorded by Istanbul Rapid Response Network (IRRN) and three Istanbul vertical array stations (IGVA) including Ataköy, Fatih and Zeytinburnu stations, during the Mw=6.5, 24.5.2014 Gökçeada and Mw=5.9, 19.5.2011 Kütahya earthquakes with the calculated accelerations by the 1D and 2D site response analyses. In this study, shear wave velocity profiles were determined based on insitu geophysical, geotechnical measurements, and laboratory tests within the Istanbul Microzonation Project. The shear wave velocity values, which are subject to some uncertainties due to some measurement methods or environmental conditions, are re-evaluated using a revision scheme to obtain the best matches between the recorded and calculated spectral accelerations by 1D site response analysis. These modified shear wave velocity profiles are later used for 1D and 2D site response analyses which in North-South and East-West directions to model peak ground and spectral accelerations on the ground surface. The results show the improvement of the calculated PGA and SA values. Finally, as another focus of this study, by modelling different symmetric spacing around the main boreholes separately in two main directions of some IRRN stations, the influence of horizontal distance on site response was investigated for 2D analyses. The results show that, in general, no unique relationship can be defined between the horizontal distance and the site response. There is an optimal spacing for each soil profile to obtain the best agreement between the calculated SA and the recorded value.