矮塔混凝土斜拉桥成桥索力优化分析

Optimization Analysis of Bridge-Completing Cable Force for Extradosed Concrete Cable-Stayed Bridges

摘要: 以常熟碧溪大桥(矮塔混凝土斜拉桥)为工程背景，基于影响矩阵方法，考虑主梁体内预应力作用，以主梁和主塔弯曲能量最小为目标函数，以主梁和主塔控制截面的内力为约束条件，进行了成桥索力优化分析。分析结果表明：优化计算获得的大桥合理成桥索力有利于减小混凝土收缩徐变和预应力损失给桥梁运营带来的不利影响；对成桥状态下进行了移动荷载分析，结果表明活载作用对结构状态影响较小；此成桥状态满足设计规范及合理成桥状态优化目标要求。

Abstract: Based on the engineering background of the Changshu Bixi Bridge (extradosed concrete ca-ble-stayed bridges (ECCB)) and by means of the influence matrix method, taking the minimum bending energy of the main girder and tower as the objective function and taking the internal force of the control section of the main girder and tower as the constraint condition, the cable force optimization analysis of the bridge was conducted. The results show that the optimized calculation of the bridge’s reasonable cable force can help to reduce the negative impact of concrete shrinkage creep and prestress loss on the bridge’s operation. The moving load has few effects on the structure state. The bridge state meets the design specification and the objective of bridge state optimization.