摘要
为考察多拱肋蝶形拱桥结构的稳定性,基于考虑钢管套箍作用的统一理论,对大跨度蝶形钢管混凝土拱桥的2类稳定问题进行了分析.通过计算特征值,得到了结构的第一类稳定安全系数;考虑结构的几何非线性和材料非线性,用荷载增量法迭代求解,得到了结构的极限承载力和第二类稳定安全系数.以太原市南中环主桥为工程背景,对该桥各施工阶段和成桥阶段的空间稳定性进行了分析.结果表明:用换算截面法和叠合单元法获得的稳定安全系数比用统一理论法获得的整体上略小,用统一理论法分析钢管混凝土拱桥的稳定性是可行的;蝶形拱桥的失稳形式以拱的面外扭转失稳为主;拱肋的初始缺陷、活载分布形式和横向风荷载等对结构稳定性均有不同程度的影响;结构的第二类稳定安全系数均小于第一类稳定安全系数.
In order to investigate the stability of bridges,based on the unified theory considering the confining action of steel tube,the first-and second-class stabilities of butterfly-shape concrete-filled steel tube arch bridges were analyzed.The first-class stability safety factor was obtained from the calculation of eigenvalue.By considering the effects of the geometry nonlinearity and material nonlinearity on the ultimate bearing capacity,the second-class stability safety factor was gained by the load incremental iteration method.By taking the main bridge on south-central ring district of Taiyuan City as the research object,the spatial stabilities of this bridge at the construction and finished stages were analyzed.The research results show that the stability safety factors obtained by the transformed section method and the composite element method are less than those obtained by the unified theory,so the unified theory can be applied to the stability analysis of concrete-filled steel tube arch bridges.The lateral torsional deformation is the primary buckling form of a butterfly-shape arch bridge,and the structure stability is influenced by the initial imperfection,the distribution of live load,cross wind and so on.The second-class stability safety factor is lower than the first-class stability safety factor.
出处
《西南交通大学学报》
EI
CSCD
北大核心
2010年第6期868-874,共7页
Journal of Southwest Jiaotong University
关键词
钢管混凝土
蝶形拱桥
统一理论
稳定
非线性
concrete-filled steel tube
butterfly-shape arch bridge
unified theory
stability
nonlinearity
