大跨悬索桥成桥状态初始构形及内力的确定方法

悬索桥结构分析的首要问题是如何确定成桥状态时缆、索、梁的空间位置(即成桥状态初始构形)和缆、索构件的内力(即单元初应变)。基于通用有限元程序,本文先用悬链线公式给出主缆的近似位置,然后通过对结构进行拆分、组合的分析过程,详细地给出了悬索桥成桥状态初始构形和缆、索内力的确定方法。对于单跨悬索桥的边跨,根据其主缆水平分力与中跨相等的原则,用悬链线公式即可给出主缆线形。最后,本文对润扬悬索桥的成桥状态进行了计算确定,并与竣工实测数据进行了对比。对比分析表明,计算结果与实测结果较为一致,本文方法具有很好的工程应用价值,可为同类大跨悬索桥的计算分析提供有益的参考。

A Calculation Method for Initial Configuration and Internal Force of Completion State of Long-span Suspension Bridge

How to determining the spatial position of structural components(named initial configuration of com- plete bridge)and their internal force(named element initial strain)is the key issue in structural analysis for suspen- sion bridge.Based on general finite element programs,the probable curve of main cable is presented firstly by catenary formulation.Then,the initial configurations of complete bridge alignment as well as the internal force in cables are determined progressively through disconnect-assemble analysis process.As for side span of single-span suspension bridge,the cable curve can be presented just by catenary formulation.It must be ensure that the horizontal force of side span cable is equal to the one of middle span.Runyang Suspension Bridge is taken for calculation as an example, and the results are compared with the test one.It shows that the methods presented in this paper can be used in struc- tural analysis for long-span suspension bridges of the same kind.