基于等待梁法的在用梁桥承载力可靠度

针对梁式桥结构显著失效模式之一———主梁的失效,研究在用梁桥承载力可靠度分析方法。从一根简支单梁出发,逐步对简支梁桥和连续梁桥的承载力可靠度分析方法进行研究。根据主梁的受力特点,确定梁桥承载力可靠度分析控制截面,分析并提出简支梁桥和连续梁桥可能的失效模式。引用增量荷载法和控制截面处不利布载相结合的方法,实现梁桥结构主要失效模式的搜寻;引入等代梁法,将多梁式结构的空间可靠度问题转化为单梁式结构的平面可靠度问题,以简化梁桥结构体系承载力可靠度的估算。最后,给出实桥应用算例。

Bearing capacity reliability for existing beam-bridge

The analytical method on bearing capacity reliability for existing beam-bridge were discussed based on the failure model of main beam, which is the most important failure model of beam-bridge. The whole research process was given gradually from the reliability analysis of a beam to the simply supported beam bridge, then to the continuous beam bridge. According to main-beam's stress characteristic, the control sections were determined and the possible failure models were also presented. The representative failure models of main beam can be searched by incremental method and disadvantage loading in the control sections. And the equal-substitute beam method can simplify the reliability estimation on bearing capacity of multi-beam bridges. This method was applied in simply supported beam bridge.