Reliability based Optimization of base Isolated Building Under Stochastic Earthquake Load Considering Random System Parameters

Abstract eng:
Base isolation (BI) has long been established as an effective tool for improving seismic performance of structures. Studies on the performance of BI system under stochastic earthquake load are notable. However, most of the studies consider system parameters as deterministic and the optimal isolator characteristics are obtained accordingly. A major limitation of the deterministic approach is that the uncertainties in the performance-related decision variables cannot be included in the parameters optimization process. The present study deals with the reliability based design of BI system under seismic excitation considering the effect of system parameter uncertainty. With the aid of matrix perturbation theory, using first order Taylor series expansion, the total probability concept is used to evaluate the unconditional response of the structures under parameter uncertainty. For this, the conditional second order information of response quantities are obtained in random vibration framework using state space formulation. Subsequently, the unconditional failure probability of the primary structure is used as the objective function in order to determine the optimum BI system. The proposed design approach, thus, is tolerant to the uncertainty and provides estimate of the enhanced risk unforeseen in the deterministic system. A lead rubber bearing isolator (LRB) isolating a multi-storeyed building frame is considered for numerical study to elucidate the effect of parameter uncertainty on the optimum performance of BI system.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket