横撑对大跨径斜拉拱桥力学性能的影响

以湘潭湘江四大桥为工程背景,分析了横撑对斜拉拱桥稳定、自由振动和抗震等力学性能的影响.首先,基于ANSYS有限元软件,建立了湘潭湘江四大桥的空间有限元模型.其次,从斜拉拱桥的特值屈曲和非线性屈曲两个方面来研究横撑对斜拉拱桥的稳定安全性和极限承载能力影响;用模态分析方法研究了横撑对斜拉拱桥的自振特性的影响;在非一致激励条件下,研究了横撑对斜拉拱桥抗震性能的影响.通过以上研究得出:较大的横撑刚度有利于斜拉拱桥稳定性的提高,但同时降低了结构的抗震性能.

Effect of Transverse Brace on Mechanical Property of Long Span Cable-Stayed Arch Bridge

The effect of transverse brace on the stability,free vibration and earthquake resistance of cable-stayed arch bridge is investigated,and Xiangtan Xiangjiang 4th Bridge is taken as an example in the paper.Firstly,a space finite element model for Xiangtan Xiangjiang 4th Bridge is established with ANSYS software.Then,based on the analysis method of eigenvalue buckling and nonlinear buckling,the effect of transverse brace on stability and limit load-carrying capacity of cable-stayed arch bridge is discussed.Contributions of transverse brace to free vibration characteristics of bridge are analyzed by the modal analysis method.The influence of transverse brace on the earthquake resistance of bridge is also studied under inconsistent excitations.The results show that increasing the stiffness of transverse brace can improve the stability of the cable-stayed arch bridge,but simultaneously make the earthquake resistance fall.