大跨度混合梁斜拉桥参数敏感性分析

Analysis of parameters' sensitiveness of long-span hybrid girder cable-stayed bridge

为了提高大跨度混合梁斜拉桥的施工控制精度,通过计算比较梁重、斜拉索张拉力、斜拉索的刚度等设计参数在成桥时对主梁挠度、主梁应力和索力的影响程度,分析了各设计参数的敏感性.计算结果表明,大跨度混合梁斜拉桥主要设计参数有梁重和拉索张拉力,而索的刚度对成桥状态影响不大.通过修正主要设计参数,同时忽略次要设计参数的影响,对荆岳长江公路大桥进行施工控制.成桥测试结果表明,拉索索力与成桥线形状况良好,均在误差控制允许的范围内,其中索力误差小于5%,主梁标高偏差小于65 mm.

In order to improve the construction control precision of long-span hybrid girder cable-stayed bridge, the sensitivity of design parameters such as the weight of girder, the cable tensile force and the stiffness of cable are analyzed through computing and comparing the influences of these parameters on the deflection of girders, the stress of girders and the cable force in the bridge＇ s completion state. It was shown by the computation results that the main parameters of long-span hybrid girder cable-stayed bridge include the weight of girder and the cable tensile force, while the stiffness of cable has little influence on the completion state of the bridge. With this approach, through modifying the main parameters and ignoring the influences of the secondary ones, the Jingyue Yangtze River Highway Bridge construction control has been successfully performed. The test results show that the cable force and the contour of the bridge are in good state and in control. The relative error of the cable force is less than 5 % and the elevation deviation is less than 65 ram.