大跨度中承式钢箱桁架拱桥空间稳定性分析  

Analysis of Spatial Stability of Long-span Half-through Steel Box Truss Arch Bridge

作　　者：江京翼 周志祥[1] 王邵锐[1] 

机构地区：[1]重庆交通大学土木建筑学院,重庆400074

出　　处：《公路工程》2015年第2期132-136,141,共6页Highway Engineering

基　　金：重庆市自然科学基金(重点)项目(2012JJB0118)

摘　　要：随着钢箱桁架拱桥跨径的增大,其空间稳定性问题更为突出,对大跨径钢箱桁架拱桥稳定性及影响因素进行分析,具有重要的实际工程意义。某桥为主跨519 m的中承式钢箱桁架拱桥,通过对其建立空间有限元模型进行线弹性稳定分析,结果表明:大跨径中承式钢箱桁架拱桥活载对稳定性影响较小,结构失稳一般表现为面外失稳,且最容易发生在拱圈无平联区域。对稳定性的影响因素进行分析表明:菱形和"K"字形对提高稳定性效果最佳;斜吊杆较竖吊杆能提高面内稳定性,但降低了面外稳定性;初始几何缺陷不会显著降低大桥的线弹性失稳荷载。With the increase of span length of steel box truss arch bridge,the problem of spatial stability becomes even more promient. So it is significant important in the practical engineering to study the stability of such bridges and its influencing factors. The bridge is a long-span half-through steel box truss arch bridge with a main span 519 m. The linear elastic stability of the structure is analyzed using the spatial finite element models. The results show that live load has little impact on the stability. The structural buckling is mainly shown by out-plane buckling of the arch and it is more likely to occur among arch ring without longitudinal bracings. The results of analysis on influencing factors of instability illustrate that diamond-shaped K-shaped longitudinal bracings are the most suitable to improve stability. Oblique than the vertical hangers can improve the stability of the inner surface,but reduces the outer surface stability. The initial geometric defects can＇t decrease significantly the critical load of instability.

关 键 词：钢桁拱 空间稳定性 有限元法 弹性屈曲 影响因素 

分 类 号：U448.224[建筑科学—桥梁与隧道工程]