An integrated simulation method for soil-structure interaction analysis of nuclear structures

This paper presents the development, implementation and application of an integrated simulation method for non-linear soil-structure interaction (SSI) analysis of nuclear structures. The integrated simulation method allows decomposition of the soil-structure system into three subsystems: the superstructure, the soil-foundation interface, and the soil domain. Each decomposed subsystem can be modelled independently using a proper finite element analysis program to accurately represent its non-linear behaviour as per the current guideline for non-linear SSI analysis of nuclear structures. The integrated simulation method is applicable to both static and dynamic analysis cases. The method was applied to the detailed SSI analysis of a realistic nuclear containment structure. The analysis was benefited by using different analysis tools for the three subsystems to capture both material and geometrical nonlinearities such as sliding and gapping at the soil-foundation interface. The integrated model was compared with the model based on the fixed-base assumption. Different results address the importance of non-linear SSI analysis for seismic performance assessment of nuclear structures.