不对称独塔斜拉桥施工过程受力分析与优化

Stress Analysis and Optimization During the Construction Process of Asymmetric Single Tower Cable-stayed Bridge

对半漂浮体系不对称独塔斜拉桥施工过程中的受力特性进行研究,对施工控制性因素及其影响进行分析。通过主塔支座水平反力和边跨支架反力优化分析,得到合理的拉索张拉和配重施加方案。研究结果表明,在不对称独塔斜拉桥施工过程中,应将塔梁连接处支座水平反力作为施工过程优化的关键因素;为控制边中跨拉索不平衡水平力,采用悬臂施工时,拉索宜分2次张拉,一张索力应与悬臂梁段自重平衡,合龙后再放张至设计索力;可根据施工工序的排布合理选择独塔斜拉桥边跨配重分批施加时机。

The stress characteristics during the construction process of asymmetric single tower cable-stayed bridges with semi floating systems are studied,and the construction control factors and their effects are analyzed.By optimizing the horizontal reaction force of the main tower support and the reaction force of the side span support,a reasonable scheme for cable tensioning and counterweight application is obtained.The research results indicate that in the construction process of asymmetric single tower cable-stayed bridges,the horizontal reaction force of the support at the tower beam connection should be the key factor for optimizing the construction process.To control the unbalanced horizontal force of the mid span cables,when using cantilever construction,the cables should be tensioned in two stages.The tension of one cable should be balanced with the weight of the cantilever beam segment,and then released to the design cable force after closure.According to the arrangement of construction procedures,the timing machine for batch application of side span counterweights of single tower cable-stayed bridges can be reasonably selected.