基于横撑非线性钢管混凝土拱桥抗震分析  

Aseismic Analysis of Concrete-filled Steel Tubes Arch Bridge Based on Nonlinear Cross Bracing

作　　者：杜骞[1] 夏修身[1] 陈兴冲[1] 孙学先[1] DU Qian;XIA Xiu-shen;CHEN Xing-chong;SUN Xue-xian(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院

出　　处：《兰州交通大学学报》2019年第4期7-11,共5页Journal of Lanzhou Jiaotong University

基　　金：国家自然科学基金(51368033,51668035);中国铁路总公司科技研究开发计划(2015G002-B)

摘　　要：基于OpenSees平台建立了钢管混凝土拱桥动力分析有限元模型,并与Midas Civil模型前五阶自振周期进行了校核.通过一条强震记录下的增量动力分析得出,拱肋3/8和5/8跨径处截面附近横撑单元最先屈服,并获得了大跨度钢管混凝土拱桥横撑非线性发展规律.分析了横撑构件采用线弹性和双线性两种本构模型时,拱脚、1/4截面和拱顶等拱肋关键截面的内力、位移结果,并对数据进行了分析比对.研究结果表明:钢管混凝土中承式拱桥在横桥向强震作用下,拱顶及拱肋与主梁连接处附近横撑均屈服.横撑采用双线性与线弹性本构模型相比,拱脚内力变化不大,拱肋1/4截面内力及拱顶内力和位移均减小,且随着横撑屈服单元增多,减小趋势越明显.Based on the OpenSees platform,the dynamic analysis model of CFST arch bridge is established and compared with the first five order natural vibration period of Midas Civil model.Through the IDA analysis of a strong earthquake record,the first brace of cross bracing element near the cross section of arch rib 3/8 and 5/8 yield first,and the nonlinear development rule of long span concrete-filled steel tubular arch bridge is obtained.When linear elastic and bilinear constitutive models are adopted for the cross braces,the results of internal forces and displacements of the key sections of arch rib,1/4 section and vault were analyzed and compared.The research results show that:Under the strong transverse earthquake action,both the transverse braces near the joint between the arch and the arch rib yield.Compared with the linear elastic constitutive models,the internal force of arch foot of the bilinear transverse bracing changes little.Both the internal force of 1/4 section of arch rib and the internal force and displacement of vault are reduced.With the increase of the number of transverse bracing element,the decreasing trend is more obvious.

关 键 词：钢管混凝土拱桥 横撑 非线性 增量动力分析 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]