On the Numerical Investigation of the Absorbing Boundaries Influence to the Dynamic Soil Structure Interaction

In this work, a computational study for the investigation of the absorbing boundaries influence to the dynamic soil structure interaction is presented. More specifically, an analysis of the influence of the Lysmer boundaries to hexahedral finite element models that are seismically excited is portrayed hereinafter. The influence to the time history analyses of the free field and the structure with the soil, the amplification factors due to the presence of the boundaries and the soil, and the maximum displacements and accelerations is investigated numerically. The seismic excitation is the Athens 1999 Earthquake which is considered as a palm force. It has been demonstrated that the absorbing boundaries influence is prominent when the ratio of the FEM width to the corresponding height is less than ten. Moreover, the amplification factor due to boundaries expresses a not usual behaviour as a result of the standing waves. Also, the soil amplification factor is slightly influenced but in all cases is estimated with a substantial accuracy while the soil structure interaction's main attributes with the decrease in the equivalent forces and the increase in the displacement is in all cases evident.