斜拉桥方案优化设计分析

Analysis of Optimal Design of Cable-stayed Bridge

为研究斜拉桥不同结构体系对结构内力的影响规律,本文以某大跨度斜拉桥为工程背景,分别选取塔梁固结体系、塔墩梁固结体系以及半漂浮体系三种结构体系,采用有限元软件分别建立不同有限元模型,分析在不同结构体系下主梁、塔柱以及桥墩各构件的内力,同时针对主梁刚度进行分析。结果表明,对于某大跨度斜拉桥采用塔梁固结体系时,各个荷载组合下主梁和塔柱的受力都相对较小,弯矩极值均小于其他两种体系,其中主梁弯矩极值最大优化幅度达到了65.28%,塔柱弯矩极值最大优化幅度达到了340.85%。采用塔梁固结体系主梁挠度值最大,但相对于其余两种斜拉桥结构体系,挠度增加不大;因此结合本工程案例,选择塔梁固结体系是可行的。

In order to study the influence of different structural systems of cable-stayed bridges on structural internal forces,this paper takes a long-span cable-stayed bridge as the engineering background,and selects three structural systems,namely tower beam consolidation system,tower pier beam consolidation system and semi-floating system,respectively,and uses finite element software to establish different finite element models to analyze the internal forces of main beams,tower columns and pier components under different structural systems.At the same time,the stiffness of the main beam is analyzed.The results show that for a long-span cable-stayed bridge using the tower beam consolidation system,the forces on the main beam and tower column under each load combination are relatively small,and the extreme bending moment is smaller than the other two systems.The maximum optimization amplitude of the extreme bending moment of the main beam is 65.28%,and the maximum optimization amplitude of the extreme bending moment of the tower column is 340.85%.The deflection of the main beam of the tower beam consolidation system is the largest,but the deflection increases little compared with the other two cable-stayed bridge systems.Therefore,combining with this project case,it is feasible to select the consolidation system of tower beam.