Non-linear seismic response analysis of the layered soil deposit using hybrid frequency–time domain (HFTD) approach

Abstract

Available seismic ground response analysis methods are categorised into linear, equivalent linear and non-linear methods that perform the analysis in the time or the frequency domain. Non-linear methods often conduct the analysis using step-by-step integration in the time domain. Despite their accuracy, these methods are usually time-consuming. On the other hand, simplicity, flexibility and less computational effort are the advantages of the frequency domain methods. In this paper, hybrid frequency–time domain procedure is used to perform seismic response of a layered soil deposit. Dynamic equation of motion is written in the frequency domain where soil response is analysed. Pseudo-forces are applied to the system in a rational iterative procedure in the time domain to evaluate the non-linear soil behavior. A computer code is written in MATLAB environment to perform current study analysis. Verification of the accuracy of the proposed method is made by comparing its results including time histories of acceleration and displacement and acceleration response spectrum to the recorded data of earthquakes. The results of the proposed method are also compared with the results of equivalent linear and non-linear methods which are provided by SHAKE and DEEPSOIL computer programs, respectively.