Seismic Risk Analysis of Bridge Structures Based on Total Probability Theorem

Abstract

Considering the uncertainties in structural capacities and seismic motions, a probabilistic-based seismic risk analysis approach for bridges is proposed in this paper. In this approach, the Total Probability Theory (TPT) is used to divide seismic risk analysis into three main steps: seismic hazard analysis; structure damage analysis; and failure probability analysis. The parameters of seismic risk analysis are assumed to be an independent and discrete Markov process, resulting in rigorous and consistent seismic risk functions for calculating the annual average probability of exceeding a designated limit state of structure under a specific level of seismic intensity. A case study of seismic risk analysis was performed on a three-span continuous rigid-frame bridge. The results show that the approach presented in the paper is applicable for the seismic risk analysis of bridge structures, and is an effective tool to assess the performance of bridge structures under earthquake actions.