Simple Models of Foundation-Soil Interactions

Abstract—This study aims to develop a series of simplified mass-spring-dashpot model to simulate unbounded soil for a foundation-soil system subjected to vertical, horizontal, rocking and torsional motions. A group of equivalent models are established by using three equivalent criteria and the coupling of horizontal and rocking motions is also considered. An optimal equivalent model is then determined to represent the best simplified model. The dynamic responses of the foundation-soil system using the optimal equivalent model are compared with those obtained by the half-space theory and by the lumped-parameter models. Since the coupling of horizontal and rocking motions is adequately considered, the optimal equivalent model is found to have more accurate results than most existing models. Moreover, the proposed model is also applied to a time-history analysis for a building-soil interaction system subjected to horizontal excitations. This proposed method may be effectively applicable to practical soil-structure interaction problems.