Soil-Structure Interaction Effects On Seismic Behaviour Of Base-Isolated Nuclear Power Plants

Abstract

The soil-structure interaction effects between the structure and its geological medium become important for massive structures such as nuclear power plants. The present study investigates the effects of soil-structure interaction (SSI) on the seismic responses of base-isolated nuclear power plant (NPP). A comparison between seismic performances of the base-isolated NPP and rigidly fixed NPP to the ground is examined considering SSI effects. In this study, a nuclear power plant structure with total height of 65.8m is modelled as a lumped mass stick model and seismic isolation system is adopted by using lead rubber bearing (LRB) isolation device. To incorporate SSI effects the underlying soil medium is assumed as a homogenous half-space and modelled by the concept of cone models. Moreover, two shear wave velocities are used in SSI system to represent the real rock site conditions of NPP structures. The results leading to conclude that the effects of SSI on seismic performances of the base-isolated NPP are negligible than the rigidly fixed NPP rested on rock sites.