永定河大桥主桥钢箱梁高腹板稳定性研究

摘要

The develop trends of domestic steel bridge are long span and special landscape requirements.Steel box girder is the main force structure bearing bridge deck load.The design method and requirement on steel box girder web stability are not disagreement at home and abroad.Especially on the deep web stability problem,the code applicable scope needs to be careful studied.Taking the steel box girder deep webs of main bridge of Beijing Yongding River Bridge on Chang'an Avenue West Extension Line as a research object,by using the fi nite element analysis method,the nonlinear buckling analysis of the second category stability was carried out.The analysis considered the stiffening rib structure and its stability requested by GB 50017—2003 Code for Design of Steel Structures and Japan steel structures code and other mainstream design codes.The unilateral cross rib scheme and bilateral cross rib scheme were comparative analyzed,fully considering the influence of welding residual stress and initial imperfection by using the finite element analysis method.The results show that the deep web stability of the bridge meets design and application requirement.%国内钢结构桥梁逐步向大跨、满足景观要求等方向发展.钢箱梁作为桥面荷载的主受力结构,针对其腹板稳定性验算问题,国内外各规范给出的设计方法不尽相同,尤其是对于高腹板稳定性问题,规范适用范围尚需深入探讨.本文以长安街西延永定河特大桥主桥钢箱梁腹板为研究对象,综合我国GB 50017—2003《钢结构设计规范》、日本钢桥规范等主流设计规范中给出的加劲肋构造和稳定性验算要求,对比分析了单侧横肋和双侧横肋2种设计方案,并利用有限元分析方法,在充分考虑焊接残余应力和初始缺陷影响的情况下,进行第2类稳定非线性屈曲分析.结果表明该桥的腹板稳定性满足设计使用要求.