基于风险的桥梁抗灾性能设计方法

Riskbased Design Method of Disasterresistance Performance for Bridge

摘要:

基于风险思想，提出了考虑灾害危险性和桥梁多级性能水平的抗灾设计方法.根据桥梁结构灾害下的性能要求，定义量化的桥梁性能目标，结合易损性分析，获得灾害下各性能水平的易损性曲线.通过易损性曲线与灾害危险性模型的卷积，获得桥梁各性能水平的概率模型，随后进一步考虑性能水平的损伤比，实现综合失效风险分析.以一斜拉桥桥塔为例，利用建立的方法对地震灾害中桥梁进行了多性能水平分析.

Abstract:

A disasterresistance design method for bridge based on risk is developed by taking account the hazard model and the multilevel performance of bridge. Considering quantitative performance objects, fragility curves of every performance level are obtained through fragility analysis. The failure risk is determined by considering the failure probability, which is calculated by convolving the fragility curve with the hazard model and the damage ratio of every performance level. A tower of cablestayed bridge in seismic district is provided to illustrate the method.