comparison of equivalent linear and nonlinear soft soil site response analysis due to near and far field excitation

the widely investigation about local site effects on strong ground motion characteristics indicate that the peak ground acceleration can be strongly affected by the linear or nonlinear behavior of soil deposit. moreover, accelerometers recorded near active faults have some important characteristics that make them different from those recorded in far-fault regions. high-frequency components in acceleration records and long-period velocity pulses are among notable specifications of such ground motions. in this paper, the one-dimensional equivalent linear method in frequency domain and nonlinear method in time domain based on total stress modeling for both approach have been performed for soft clayey profile. in order to evaluate the real behavior of the site response due to incident waves, six normalized near field and far field acceleration time histories are selected for input excitation. the analysis results denoted that mean acceleration response spectra for nonlinear method is less than the corresponding values in equivalent linear method.