AN EVALUATION METHOD FOR SEISMIC ISOLATION EFFECT IN SITING OF A NUCLEAR FACILITY

Seismic reliability is one of the most appropriate indices to compare several site/design alternatives of important facilities from the view point of seismic safety. A method is demonstrated here to compare seis mic reliabilities of two buildings, with and without seismic base isol ation, unbiasedly. Particular attentions are paid for ground motion ch aracteristics and nonlinear load deformation relationships to avoid bi ases. The method is applied to an example of siting/design issues, sit uation of which is similar to an experimental fusion facility. Referen ce buildings are simply modeled and their annual probabilities of fail ure are evaluated. It is confirmed that an unbiased comparison between base isolated and non-base isolated buildings is reasonably possible. It is also confirmed in terms of reliability that introducing seismic base isolation system is an effective means for siting/design issues. (C) 1998 Elsevier Science Ltd. All rights reserved.