摘要
为研究大跨人行悬索桥在斜风作用下的静风稳定性,提出了一种实用的斜风作用下大跨桥梁静风稳定性分析方法。在小偏角下,忽略斜风对于桥梁断面气动外形的影响,基于正交分解方法推导了完全考虑桥梁静风空间变形影响的斜风静力荷载理论表达式,编制内外两重迭代的大跨桥梁斜风静力稳定分析程序,进行了420 m主跨人行悬索桥非线性静风稳定分析。结果表明:斜风静力荷载是有效风攻角与有效风偏角的函数,精确考虑斜风静力荷载作用,要求对有效风攻角和有效风偏角同时进行迭代;静风失稳形态是以主梁扭转变形为主的复杂弯曲扭转耦合的三维空间变形状态,在静风弯扭空间大变形作用下,背风侧缆索系统应力大幅卸载,最终背风侧抗风缆应力接近完全卸载导致悬索桥系统刚度丧失,进而发生静风失稳;该类大跨人行悬索桥最不利静风稳定来自于法向风,小角度斜风对该桥静风失稳临界风速影响不大。
A practical method is proposed to study nonelinear aerostatic stability of the long-span suspension bridge under skew wind.Neglecting the effect of skew wind on the aerodynamic shape of the bridge deck at small angles of yaw,the theoretical expression of the skew wind aerostatic load considering the influence of the aerostatic spatial deformation of the bridge is deduced based on the orthogonal decomposition method,and then the double iteration program for aerostatic stability analysis of long-span bridge is worked out.This paper takes a 420 m main span suspension bridge as an engineering example of aerostatic stability analysis.The results show that the skew wind aerostatic load is a function of the effective wind attack angle and the effective wind yaw angle,and it is necessary for accurately considering the aerostatic load of skew wind to iterate the effective wind attack angle and the effective wind yaw angle simultaneously;aerostatic instability of long-span suspension bridge is a three-dimensional deformation state of complex bending-torsional coupling of the main girder,and the stress unloading of the leeward cable system has been increasing with the development of aerostatic bending-torsional deformation.Finally,the stress of leeward wind-resistant cable is close to zero leading to the suspension bridge system stiffness loss and aerostatic instability.The minimum critical wind speed of aerostatic instability of the long-span suspension bridge results from the normal wind and the skew wind with small yaw angle has little effect on the critical wind speed of aerostatic instability of the long-span suspension bridge.
作者
管青海
王剑
李加武
刘健新
GUAN Qinghai;WANG Jian;LI Jiawu;LIU Jianxin(School of Transportation Engineering,Shandong Jianzhu University,Jinan 250101,China;Key Laboratory of Highway Bridge and Tunnel in Shaanxi Province,Chang’an University,Xi’an 710064,China;Tianjin Key Laboratory of Civil Structure Protection and Reinforcement,Tianjin Chengjian University,Tianjin 300384,China;Wind Tunnel Laboratory,Chang’an University,Xi’an 710064,China)
出处
《山东建筑大学学报》
2022年第4期79-85,共7页
Journal of Shandong Jianzhu University
基金
国家自然科学基金青年科学基金项目(51408399)
山东省自然科学基金面上项目(ZR2021ME104)
天津市自然科学基金项目(18JCQNJC08300,17JCYBJC22300)
山东省交通运输厅科技计划项目(2020B69)
陕西省公路桥梁与隧道重点实验室(长安大学)开放基金项目(300102219532)
山东建筑大学博士科研基金项目(X20082Z)。
关键词
桥梁工程
斜风静力稳定性
数值模拟
大跨悬索桥
静风荷载非线性
几何非线性
bridge engineering
skew wind aerostatic stability
numerical simulation
long-span suspension bridge
aerostatic load nonlinearity
geometric nonlinearity
