EFFECTS OF NEAR-FAULT ON DYNAMIC RESPONSE OF A STRUCTURE EXCITED BY EARTHQUAKE WAVES

The goal of this study is to concentrate on the near-fault effects on the structure behavior of underground excitation. To figure out the exact behavior of the structure, a simple model is chosen. During the solution process, dynamic soil-structure interaction is taken into account. The physics of the problem is very complicated owing to the reflection of the waves from the free surface and fault boundary, and the scattering of the waves from the foundation and transmission of the energy into the structure. The materials of the soil and the structure are considered as homogeneous and isotropic, and the foundation is assumed as a rigid body. Response of the structure in the frequency domain is derived using Wave Function Expansion Method and Image Method. Numerical results show that when the structure approaches the fault, the amplitudes of the foundation and relative displacements of the structure are getting bigger. The incident angles of the waves have a big influence on the response of the structure close to the fault, therefore the standard design code should not be applied in the analysis of the structures. It is concluded that near-fault effects should be considered carefully.