拱桥悬浇扣挂施工中最大悬臂状态下的索力调整

为寻找合龙前的最合理扣索索力,将最优化理论与正装计算运用到拱桥施工至最大悬臂状态下扣索索力的确定与调整中,利用有限元分析软件ANSYS的单元生死和优化功能,编制了拱桥施工过程中的索力优化程序。该优化计算采用1阶分析法,将有约束问题通过添加罚函数转化为无约束问题,以成桥后的拱圈截面控制弯矩最小为目标函数、扣索索力为设计变量,对合龙前的扣索索力逐根调整获得理想成桥内力,并将其应用于实际工程。结果表明,该方法优化效果明显,可有效改善成桥后的拱圈受力,是拱桥施工过程分析的有效工具,具有一定的应用价值。

Optimization of Cable Forces before Joining during Cantilever Construction for Arch Bridge

In order to find the rational cable force,a method combining optimization theory and orderly-erection analysis is introduced to solve this problem.It can calculate the suitable cable forces before joining during cantilever construction of long span arch bridges.Corresponding programs for this analysis is compiled based on ANSYS which has the advantage of "element birth and death" and optimization functions.First order method is introduced in optimization to change constrained optimization to unconstrained optimization.The critical moment of arch ring is considered as object function,and the cable force is considered as design variables.A rational finished state is reached by adjusting every cable force.It is applied to an actual project.The result indicates that this method is an effective tool on construction analysis as it can obviously refine internal force of arch ring on completion state.