Spatial Nonlinear Cable Force Optimum in Two Stages for Thousand-Meter Scale Cable-Stayed Bridge

Based on the problem of construction control technology of cable-stayed bridge,authors presented a cable force optimum method in two stages for cable-stayed bridge,where the first order optimum method was adopted to determine the rational construction state and reasonable finished dead state of a thousand-meter scale cable-stayed bridge.At first,the square sum of girder elevation errors and the bending strain energy of the girders and the cable tower of cable-stayed bridge in finished dead state were the objective function,and the different biased weight coefficients were attained.By making the objective function least,the tension force of cables as well as the prearranged angle of girders in construction state was obtained.Using spatial nonlinear FEM,the actual cantilever construction process of steel box-shaped girders was simulated.After the bridge was closed,the maximum and minimum bending moment of the girders and the cable tower were the objective function;a reasonable adjustment value of the cables force was obtained.The result shows that this method is effective and feasible.