Sensitivity analysis for the distribution of maximum responses by seismic isolation system parameters using the stochastic response database

The seismic performance of nuclear power plants can be improved by installing the proposed seismic isolation system. Due to the characteristics of this system, while acceleration seismic response and base shear can be reduced, the displacement seismic response of the isolated structure increases. Therefore, the restriction of excessive displacement responses becomes critical to the design and safety assessment of isolated structures. Such seismic design and safety assessment requires a seismic response distribution, which itself necessitates a large number of nonlinear dynamic analyses. However, the stochastic response database can directly estimate the maximum seismic response distribution of an isolated structure without nonlinear dynamic analyses. In this study, a sensitivity analysis was performed using the stochastic response database for the isolated structures that affect the maximum seismic response distribution. First, the important seismic isolation parameters were selected, followed by an investigation into the effects these parameters have on the mean and standard deviation of the maximum seismic response distribution of the isolated structure. It is believed that this information will be useful in the seismic design and safety assessment of nuclear power plants with seismic isolation systems.