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.