系杆拱桥吊杆更换设计中的索力优化

Cable Force Optimization of Replacing Suspender Design of Tied-arch Bridge

利用索力优化理论,分别以索力均匀性和拱肋弯矩平方和作为优化的目标函数对系杆拱桥在吊杆更换设计中的索力进行了优化。结果表明以索力均匀性为目标函数的优化方法能有效提高吊杆索力的均匀性,且优化后索力与优化前索力相差不超过10%。而以拱肋弯矩最小为目的的索力优化方法能有效减小拱的弯矩但同时将带来索力的不均匀性,在索力调整的过程中,最大索力改变量可达41%。根据旧桥加固设计的原则,为了不对结构的现有状态造成较大改变,最后推荐采用索力均匀性优化结果作为吊杆更换后的目标索力。

By cable forces optimization theory, respectively, tension uniformity and arch rib＂ s bending moment squares as objective function are used to optimize the cable force of replacing suspender design of tied-arch bridge. The results show that the optimization method using tension uniform as objective function can make the cable ten- sion more uniform, and the difference between the optimized and the un-optimized cable tension is no more than 10%. The optimization method using arch rib＂ s bending moment squares as objective function can reduce the bending moment largely, but the cable tension optimized is more non-uniform. The maximum cable force changed up to 41% in the process of cable force adjustment. Under the old bridge reinforcement design principles, the struc- ture of the existing state in order not to cause major changes, and finally recommended cable force optimization re- suits as uniform boom target replacement cable force.