CFRP索斜拉桥的动力特性分析

采用CFRP拉索是解决传统钢拉索腐蚀退化问题的根本途径,由于CFRP的自重仅为钢材的1/5,当跨径很大时,CFRP索斜拉桥的动力特性与钢索斜拉桥的动力特性会有区别,为此,以探索性设计的跨径为1 000 m的CFRP索斜拉桥和钢索斜拉桥为例,采用有限元法对比分析了2种拉索斜拉桥主要的动力特性,并研究了成桥初应力对斜拉桥动力特性的影响。鉴于当前对影响斜拉桥动力特性的一些关键参数少有系统研究的状况,详细分析了不同结构体系、辅助墩设置个数、拉索空间布置型式、边中跨跨径之比等参数,对CFRP索斜拉桥的动力特性的影响,得出了若干结论,为CFRP索斜拉桥的优化设计提供理论依据。

Dynamic Characteristics Analysis of Cable-Stayed Bridge with CFRP Cables

Traditional steel cables are prone to erosion and degeneration,and using CFRP cables is an essential approach to settle this problem. For the deadweight of the CFRP cable is only 20% of that of the steel cable,the dynamic characteristics of the both cable-stayed bridges will be different when span is extra long.The dynamic characteristics of a 1 000 m-span cable-stayed bridge with CFRP cables and another one with steel cables are analyzed contrastively using the finite element method in this paper, and the influence of initial stress on the dynamic characteristics is studied.Currently,the design parameters which influence the dynamic characteristics of the cable-stayed bridge are less studied systemically,so the influences of design parameters,such as structural system,the numbers of auxiliary piers,the layout type of cable-plane,the ratio of side span and main span,on dynamic characteristics of the cable-stayed bridge with CFRP cables are investigated.Some conclusions are indicated,which provides theoretical basis for optimization design.