Seismic response analysis of soil profile: comparison of 1D versus 2D models and parametric study

One of the most important parts of geotechnical earthquake engineering is evaluation of the ground motion due to incident earthquake. Seismic ground response evaluation can be categorized into time and frequency domain methods. In this study, an applied method is proposed to evaluate 2D ground response analysis in frequency domain. The results are presented in terms of peak acceleration and velocity diagrams as well as the diagrams of 2D/1D results using four real earthquakes, two in the far field and two in the near field as an incident waves. The accuracy of the proposed method is shown by comparison of results obtained using current method with those of 1D method in free field condition. Then, to evaluate the effect of irregular topographies on seismic ground response, parametric study is carried out on empty valleys and diagrams of amplification factors have been presented. The obtained results confirm the necessity of 2D modeling and the use of precise and applied methods in the case of irregular topography. The superiority of the proposed 2D method than 1D method is elimination of limiting assumption of 1D method such as horizontal bedrock and parallel soil layer despite its simplicity and practicality.