A Hybrid Probability-Convex Model for the Seismic Demand Analysis of Bearing Displacement in the Benchmark Base-Isolated Structure

摘要

An analysis was performed on the Benchmark base-isolated structure using both a convex model to simulate the uncertainties of the isolated structural parameters and a random model to simulate the uncertainties of the seismic input. A new method for calculating the fragility curves of bearing failure in the isolated structure when considering the above two uncertainties is proposed within the framework of the performance-based seismic evaluation of structures proposed by the Pacific Earthquake Engineering Research Centre (PEER), based on a full probability theory. A comparison of the calculations showed that the seismic fragility of Benchmark base-isolated structure would be underestimated if the uncertainties of the structural parameters were not considered. The sensitivity analysis of the maximum bearing displacement in the Benchmark base-isolated structure demonstrated that the mechanical parameters of the isolation bearing imparted the most significant impact on the maximum base displacement, with less significant impacts on the mass of the super structure and insignificant impacts on the stiffness of the superstructure. Based on these results, two new methods were proposed for analysis of the seismic demand of the bearing displacement, i.e., the robust seismic demand analysis and the hybrid seismic demand analysis.