基于响应面法的斜拉桥静力体系可靠度

The static system reliability of cable-stayed bridges using the response surface method

针对斜拉桥静力体系可靠度分析中隐式功能函数重构和多种失效模式的特点,提出了一种基于响应面法的体系可靠度分析方法。该方法有3个步骤:首先基于响应面法,将斜拉桥各失效模式的功能函数进行显式化,然后计算各功能函数间的相关系数,最后由窄界限法得出结构的体系可靠指标。建立了斜拉桥结构体系可靠度的数学模型,给出了体系可靠度的分析步骤,以主跨420m的混凝土斜拉桥为工程背景,展开了体系可靠度研究。研究结果表明:响应面方法在斜拉桥体系可靠度分析中具有适用性,得出了运营期斜拉桥体系可靠度的敏感参数和两条主要失效路径。

A system reliability method for the analysis of cable-stayed bridges is proposed to describe the characteristics of cables-stayed bridges with the explicit performance functions and multiple failure modes. There are three main steps in this method shown as follows：Firstly,the performance functions of cable-stayed bridges are explicit using a response surface method. Secondly, coefficient associations of multiple failure modes are calculated. Finally the system reliability index are obtained using the narrow bond method.The mathematical models of cable-stayed bridges are established and the analysis steps are given. A concrete cable-stayed bridge with a main span of 420 m is selected as a numerical example.The results indicate that the response method is feasibile during system reliability analysis of cable-stayed bridges, and then the sensitivity parameters and the main failure components are obtained.