Disaster Prevention Research Institute, Kyoto University
Abstract
In earthquake engineering, it is important to estimate reasonably the effects of the ground characteristics on the earthquake responses of above-ground structures. In this paper, the ground characteristics in an elastic range are represented as the dynamic ground compliance of a foundation on an elastic half-space that means a force-displacement transfer function of an elastic ground-foundation system. Supposing bilinear hysteretic restoring force characteristics in an above-ground structure and an elasto-plastic boundary layer underneath the foundation, the nonlinear transient responses of a ground-structure system subjected to horizontal ground acceleration excitations are analyzed in a wide parameter range. The random time functions obtained through a noise generator are used for this response analysis as ground acceleration excitations. As a result of the present study, it is pointed out that an interaction effect of the ground may act advantageously on a structural earthquake response in usual cases, while a disadvantageous effect should be considered when large plastic behaviours of structures are anticipated during earthquakes
