A frequency domain approach to evaluate 2D seismic site response: application to the real case

The seismic response obtained at the ground level can be quite different in terms of load characteristics compared with incident wave applied to the bedrock. These changes may be due to soil conditions and topography of the area. In this study, a practical approach is proposed in the frequency-domain to evaluate two-dimensional seismic ground response using transfer functions. To use the formulation of the proposed approach, a program was written called “2DTF”. The linear 2DTF software is promoted to equivalent linear program, and then two real cases of the Adames region during September 7th, 1999 earthquake are adopted for further study. These case studies have different characteristics, including free fields and areas where topography has a direct effect of changing the nature of the incident seismic waves. The superiority of the proposed two-dimensional over the conventional one-dimensional methods (despite its simplicity and practicality) is its capability to simulate different soil layering conditions and surface irregularity with high speed and accuracy. Numerical case studies show that using the 2DTF program provides reasonable and consistent results with local observations as well as verified research.