摘要
针对目前加固技术对改善大跨度连续箱梁桥承载能力有限等情况,引入非自平衡张弦梁结构(NSE-BSS),对大跨度连续箱梁桥非自平衡张弦梁结构(NSE-BSS)加固方案进行研究。NSE-BSS由上弦刚性受压构件、下弦拉索和撑杆组成,通过上弦刚性受压构件沿主梁底板下缘布置,使整个NSE-BSS加固于主梁下部。以重庆奉云高速公路孙家沟大桥为背景,采用有限元分析方法,考虑标准结构、超载、预应力损失影响因素,针对4种NSE-BSS结构设计方案,分析了最大效应荷载加载下不同撑杆布置和拉索张拉力下桥梁的承载能力。研究结果表明,NSE-BSS可以有效地提高大跨度连续箱梁桥的承载能力,且在超载、预应力损失影响因素下加固效果更明显,撑杆由竖撑和斜撑组合的张弦梁结构GH-XS和DG-XS方案加固效果更优。
The existing strengthening methods are considered having limited effect in improving the load bearing capacity of long-span continuous box girder bridge.In this study,the nonself-equilibrium bowstring beam structure（NSE-BSS）is introduced,to study the schemes of using NSE-BSS to strengthen long-span continuous box girder bridge.The NSE-BSS is composed of the upper chord rigid compressive components,lower chord cables and struts.By installing the upper chord rigid compressive members along the lower edge of the main girder base plate,the whole NSE-BSS was strengthened to the bottom of the main girder.The Sunjiagou Brige on ChongqingFengyun Expressway was taken as the study background.The finite element method was used to analyze four BSE-BSS structural design schemes by considering the influential factors,including standard structure,overloading and prestress loss.Under the maximum load effect applied,the load bearing capacity of the bridge with different strut arrangement and cable tensioning force was analyzed.The results of the study indicate that NSE-BSS can effectively improve the load bearing capacity of long-span continuous box girder bridge,and the strengthening effect would be more apparent under the influence of overloading and prestress loss,and the bowstring beam structures of GH-XS and DG-XS with combination of vertical struts and oblique struts have better strengthening effect.
出处
《世界桥梁》
北大核心
2015年第5期80-84,共5页
World Bridges
基金
北京市自然科学基金项目(8122007)
关键词
箱梁桥
大跨度
非自平衡
张弦梁
加固
超载
预应力损失
有限元法
box girder bridge
long span
non-self-equilibrium
bowstring beam
strengthening
overloading
prestress loss
finite element method
