大跨径铁路钢管混凝土系杆拱桥稳定性分析  

Stability analysis of long span railway CFST tied-arch bridge

作　　者：季日臣[1] 石明星[1] 

机构地区：[1]兰州交通大学土木工程学院,兰州730070

出　　处：《振动与冲击》2011年第8期87-91,共5页Journal of Vibration and Shock

基　　金：国家自然科学基金项目(10902045);兰州交通大学"青蓝"人才工程基金项目(QL-05-13A)

摘　　要：以现有拱桥稳定计算理论为指导,建立了格丑沟特大桥主桥136 m跨度铁路钢管混凝土系杆拱桥的空间有限元模型,给出了该桥在特定的荷载工况下的稳定系数及失稳模态,结果表明:结构的失稳主要表现在拱肋的面外失稳,弹性屈曲系数均大于一般要求(4～5),弹性稳定满足要求。考虑了非线性影响,对拱肋进行了逐级加载,得到了拱肋的极限荷载,并给出了拱肋达到极限荷载时各控制截面的竖向位移和横向位移,通过比较得出材料非线性对本桥稳定的影响大于几何非线性的影响。并以大量计算结果为依据,揭示了横撑布置形式、拱肋内倾角、矢跨比对该桥稳定性的影响。Under the guide of the existing arch bridge stability theory, the three dimensional finite element model was built for the 136m span tied-arch bridge with railway concrete-filled steel tube on the main bridge of Gechougou bridge. Its stability factor and the instability mode were given under the specific load condition. The results illustrate that the structural buckling is mainly shown by out-plane buckling of the arch, and elastic buckling coefficients are greater than the general requirement of （4 - 5 ）, which satisfies the requirement of the bridge elastic stability. Considering the nonlinear effects, under progressively loading on the arch ribs, the ultimate loads of the arch ribs were obtained, and the vertical and transverse displacements at each controlling section when the loads on the arch ribs reach the ultimate loads were provided. The effect of material nonlinearity on the stability of the bridge is greater than that of the geometric nonlinearity by comparison. According to lots of computing data, the effects of transverse brace layout, arch rib inclination angle and ratio of height to span on the stability of the bridge were revealed.

关 键 词：钢管混凝土 系杆拱桥 稳定分析 有限元模型 弹性屈曲 非线性 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]