Simple Method for Considering Soil-Structure Interaction in Three-Dimension Infinite Element Model of Nuclear Power Plant Building

In order to equivalently disperse the lumped soil dynamic stiffness of half space for the raft foundation of 3-D nuclear power plant building, the formula of spring-damping model of considering soil-structure interaction（SSI） for 3-D nuclear power plant building is deduced based on the lumped mass model considering SSI. This method of equivalently disperse is validated by modal analysis and dynamic time history analysis. This method solves the soil dynamic stiffness firstly, and then exerts the spring-damping element at the raft foundation of 3-D nuclear power plant building, which is easier and simpler to realize, compared to other artificial boundary methods.