千米级斜拉桥空间非线性两阶段索力优化

针对斜拉桥的施工控制技术问题,提出了斜拉桥两阶段索力优化的方法,采用一阶最优化计算方法来确定某千米级斜拉桥在施工状态和成桥状态下的合理索力。首先将斜拉桥成桥后的线形和梁塔的最小弯曲应变能设为目标函数,通过对目标函数的最优化处理,求出各施工阶段的斜拉索索力和主梁的预转折角,用空间非线性有限元法模拟钢箱梁的悬臂拼装过程;成桥后,将斜拉桥梁塔的最大和最小弯矩设为目标函数,求出斜拉索索力的合理调整值。计算结果表明:该方法是可行的,结果也是合理的。

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.