斜拉桥辅助墩的合理数量及最优位置研究

Research on Reasonable Number and Optimal Position of Cable-stayed Bridge Auxiliary Pier

文章以某PC斜拉桥为工程背景,建立了空间有限元模型,根据辅助墩对斜拉桥力学性能的影响,研究辅助墩设置的合理数量以及最优位置。研究结果表明:设置辅助墩能很大程度上改善主梁、索塔、尾索的受力和主梁的竖向变形,其中设置单个辅助墩主梁应力幅最大值可降低50%,索塔下塔柱的弯矩幅最大值可减小60%以上,边跨尾索应力幅最大值减小超过50%;在兼顾桥梁结构受力、建设成本以及施工周期的情况下,设置单个辅助墩是最合理的;单个辅助墩最优位置为距边墩0.3倍边跨跨径处。其研究成果将为同类型桥梁设计提供参考。

With a PC cable-stayed bridge as engineering background,this article established the space finite element model,and according to the impact of auxiliary pier on the mechanical properties of cable-stayed bridge,it studied the reasonable number and optimal position of auxiliary piers.The research results showed that:the auxiliary pier can greatly improve the force of main beam,cable tower,and tail cable as well as the vertical deformation of main beam,in which the single auxiliary pier can reduce the maximum stress ampli-tude of main beam by 50%,the maximum bending moment amplitude for lower column of cable tower can be reduced by more than 60%,while the maximum stress amplitude for tail cable at side span is reduced by more than 50%;in the case of considering the force of bridge structure,construction costs and construction period,to set a single auxiliary pier is most reasonable;the optimal position of single auxiliary pier is at 0.3times of side span diameter from the side pier.The research results will provide the reference for the design of same type of bridges.