ABSTRACT
The influence of local site effects on ground motion characteristics are well demonstrated through several earthquakes (Loma Prieta, 1989; Mexico City, 1985; Chichi, 1999; Kobe, 1995; etc.) During these earthquakes the ground motion parameters such as motion amplitude, frequency content and duration of the ground motion as well as response spectra changes because the seismic wave propagation medium has changed from rock to soil and the seismic waves are adapted to the new medium. In the engineering point of view, although the earthquake waves may travel through tens of kilometers of rock and often less than a hundred meter of soil, the soil plays a very important role in determining the characteristics of the ground surface motion (Kramer, 1996). Therefore, considering an appropriate soil behavior model is a very important issue to actually simulate earthquake site response in seismic ground response analysis.
