大跨人行悬索桥非线性静风失稳发展过程分析  

Analysis of Development Process of Nonlinear Aerostatic Instability of a Long Span Pedestrian Suspension Bridge

作　　者：管青海 张凯[2] 李加武[3] 刘健新[3] 

机构地区：[1]天津城建大学天津市土木建筑结构防护与加固重点实验室,天津300384 [2]天津市市政工程设计研究院,天津300051 [3]长安大学风洞实验室,陕西西安710064

出　　处：《桥梁建设》2018年第1期76-81,共6页Bridge Construction

基　　金：天津市应用基础与前沿技术研究计划项目(15JCYBJC48800);天津市土木建筑结构防护与加固重点实验室开放课题(12030504);天津市企业博士后创新项目择优资助计划项目(2015-003)~~

摘　　要：为研究大跨人行悬索桥非线性静风失稳的内在原因,以主跨420m天蒙人行悬索桥为背景进行分析。综合考虑几何非线性与静风荷载非线性,采用内、外双重迭代算法从定性与定量的角度分析该桥非线性静风失稳发展过程及失稳临界形态。结果表明:大跨人行悬索桥静风失稳发展路径为,不断非线性增大的加劲梁位移牵连主缆和抗风缆产生相对于加劲梁的竖向位移,使主缆和抗风缆逐渐消减拉应力,直至抗风缆接近松弛而失稳;静风失稳临界形态是以加劲梁扭转变形为主、竖弯变形为辅的复杂弯-扭耦合空间变形状态;静风失稳内在原因为,静风升力和升力矩随附加风攻角的增长不断增大,加劲梁和缆索系统的静风位移持续增大并产生相对竖向位移,导致缆索系统刚度大幅卸载。To study the inherent causes of the nonlinear aerostatic instability of long span pe-destrian suspension bridge, the Tianmeng Pedestrian Suspension Bridge having a main span of 420 m was taken as an analysis object and comprehensively considering the geometric nonlinearity and the aerostatic load nonlinearity, the inner and outer double iteration algorithm was used to qualita-tively and quantitatively analyze the development process of the nonlinear aerostatic instability and the critical state of the aerostatic instability of the bridge. The results of the analysis reveal that the development path of the aerostatic instability of the long span pedestrian suspension bridge is that the nonlinearly increasing displacement of the stiffening girder of the bridge causes the main cables and wind cables to have the vertical displacement that is relative to the girder, makes the tensile stresses of the cables gradually reduce and until the wind cables approach to the relaxation, causes the aerostatic instability to occur. The critical state of the aerostatic instability is the spatial deformation state of the complex bending and torsion coupling characterized mainly by the torsiondeformation and secondarily by the vertical bending deformation of the girder. The inherent causes of the aerostatic instability are the aerostatic lift and the incessant increase of the lift moment chan-ging with the increase of the additional wind attack angles. The incessant increase of the aerostatic displacement of the girder and the cable systems and the produced relative vertical displacement all results in the great unloading rigidity of the cable systems.

关 键 词：悬索桥 人行桥 静风失稳 双重迭代算法 失稳过程 失稳临界形态 非线性分析 

分 类 号：U448.25[建筑科学—桥梁与隧道工程] U448.11[交通运输工程—道路与铁道工程]