开口薄壁截面简支桥梁约束扭转的正应力分析

Analysis on Normal Stress of Restrained Torsion for Open Thin-wall Section Simple-supported Bridge

孟买地铁一号线高架简支桥梁采用了不对称开口薄壁截面梁的设计,这是一种近些年开始在城市轨道交通领域流行的新型结构,具有轻巧美观等特点。由于开口截面梁的扭转刚度相对较小且截面不对称,约束扭转效应显著,尤其是在曲线段。在对结构进行设计分析时,不能忽略扭转引起的应力效应。以孟买地铁一号线的简支曲线桥梁为例,介绍应用于该项目的约束扭转应力效应的分析方法。

The design of asymmetric open thin-wall section beam is used for the elevated simple- supported bridge in Metro Line 1 of Mumbai.This is a newstructure becoming popularly in recent years for the urban rail transit,and has the characteristics of legerity and beauty.Owing to the relatively small torsional rigidity and the asymmetric section,the effect of restrained torsion is remarkably especially in curve section.While performing the analytic design for the structure,the stress effect caused by the restrained torsion should not be neglected.Taking the simple-supported curve bridge in Metro Line 1 of Mumbai as an example,this article introduces the analysis method used for the stress effect of restrai ned torsi on in this project