目前桥梁可靠度分析中缺乏对桥梁实际失效模式的分析和资料,使得传统的体系可靠度分析思路对桥梁进行评估带有很大的不确定性,因而本文根据桥梁结构可靠度理论与结构地震易损性的研究现状,并结合传统可靠度分析中的现有观念与常用方法,提出了基于结构易损性分析的公路桥梁可靠度方法。该方法利用结构易损性分析的优势,根据选定的损伤准则来计算结构不同构件在随机荷载下的失效概率,能够给出结构各个构件的易损性曲线来判定出结构的最不利位置,从而为随后的结构体系可靠度分析提供便利。本文以地震荷载为例,给出了基于结构易损性分析思路的桥梁可靠度分析实例,以便具体地阐述这种思路.
At present, the reliability analysis of bridges lacks of the investigation on the actual failure mode of the bridges at the system level, making the traditional system reliability analysis involving a lot of uncertainties in bridge evaluation. In this study, a new method based on the structural vulnerability analysis is proposed to study the reliability of highway bridges according to the research status of the bridge structural reliability theory and seis- mic vulnerability of structure, the existing idea, and the current commonly used reliability method. By taking ad- vantage of the merit of structural vulnerability analysis, this method calculates the failure probability of different structural components under any stochastic load according to the chosen damage calculation criteria, gives the struc- tural vulnerability curves to determine the most unfavorable one of the components, and therefore makes the follow- ing reliability analysis convenient. A seismic case study is presented to give the details of the specific analysis process of bridge reliability analysis based on structural vulnerability analysis.