异形塔混合结构斜拉桥初始张拉力优化

Optimization of initial tension of cable-stayed bridgewith mixed structure of special-shaped tower

为探究异形塔混合结构斜拉桥合理斜拉索初始张拉力,进一步优化成桥状态下斜拉索内力分布,以某跨径布置为(2×30)+(2×60)+(2×30)m的异形塔混合结构斜拉桥为研究对象,基于影响矩阵原理,对斜拉索初始张拉力进行优化分析,计算斜拉索合理初始张拉力,并以设计成桥索力和优化后初始张拉力作为斜拉索初始张拉力的两种不同工况,对不同初始张拉力下桥梁结构响应进行对比分析。结果表明:影响矩阵法对异形塔混合结构斜拉桥初始张拉力优化效果良好,优化后的斜拉索内力趋近于设计成桥索力,且初始张拉力优化后,异形塔混合结构斜拉桥主梁弯矩整体分布更为均匀,主梁整体竖向位移相比优化前降低38.2%,在改善结构受力的同时亦对桥梁线形起到了管控作用。本文成果可为同类型桥梁斜拉索初始张拉力优化提供一定的借鉴与参考。

In order to explore the reasonable initial tension of the cable-stayed cable of the mixed-structure cable-stayed bridge with special-shaped tower,and further optimize the distribution of the internal force of the cable-stayed cable in the state of the bridge,a span of special-shaped tower mixed structure cable-stayed bridge is arranged as(2×30)+(2×60)+(2×30)based on the principle of influence matrix,the initial tension of the cable-stayed cable is optimized and analyzed,the reasonable initial tension of the cable-stayed cable is calculated;while taking the designed bridge cable force and the optimized initial tension as the initial tension of the cable-stayed cable,the response of the bridge structure under different initial tension is compared and analyzed.The results show that the influence matrix method has a good effect on the optimization of the initial tension of the cable-stayed bridge of the mixed structure of the special-shaped tower.The internal force of the optimized cable-stayed cable tends to be designed as the bridge cable force,and after the initial tensile force is optimized,the overall distribution of the bending moment of the main girder of the cable-stayed bridge with mixed structure of special-shaped tower is more uniform,and the overall vertical displacement of the main girder is reduced by 38.2%compared with that before optimization,which not only improves the structural force,but also plays a controlling role in the bridge alignment.The results can provide a certain reference for optimization of the initial tension of cable-stayed cables for the same type of bridges.