移动车辆作用下大跨度悬索桥梁端纵向位移机理  

Girder end longitudinal displacement mechanism of long-span suspension bridge under moving vehicles

作　　者：黄国平 胡建华[1,3] 华旭刚[1] 王连华 崔剑峰[4] HUANG Guoping;HU Jianhua;HUA Xugang;WANG Lianhua;CUI Jianfeng(Key Laboratory for Wind and Bridge Engineering of Hunan Province,Hunan University,Changsha 410082,China;College of Civil Engineering,Hunan City University,Yiyang 413000,China;Hunan Communication&Water Conservancy Group Ltd.,Changsha 410004,China;Hunan Provincial Communications Planning,Survey&Design Institute Co.,Ltd.,Changsha 410011,China)

机构地区：[1]湖南大学风工程与桥梁工程湖南省重点实验室,长沙410082 [2]湖南城市学院土木工程学院,湖南益阳413000 [3]湖南省交通水利建设集团有限公司,长沙410004 [4]湖南省交通规划勘察设计院有限公司,长沙410011

出　　处：《振动与冲击》2021年第19期107-115,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金(51808210);湖南省科技人才托举工程(2019TJ-Y08);湖南省自然科学基金(2021JJ50143)。

摘　　要：为研究大跨度悬索桥在车辆荷载作用下梁端纵向位移的产生机理。基于挠度理论分析了悬索桥在非对称竖向荷载作用下的变形特征,推导了移动荷载作用下悬索桥梁端纵向运动方程和共振速度,并采用等效纵向荷载研究移动荷载作用下悬索桥纵向位移响应规律。以一大跨度悬索桥为实例,研究了移动竖向荷载作用下的悬索桥梁端纵向位移的规律及影响。结果表明:在移动荷载作用下,主梁发生以等效纵向扰动频率为主的纵向受迫振动,当移动速度较小时主要表现为拟静态效应,随移动速度增大动态效应增强;结构阻尼、阻尼器及支座摩阻力均对纵向位移有抑制作用,支座摩阻力对梁端位移的影响不可忽略;中央扣的设置能有效降低移动车辆作用下的梁端纵向累积位移,但梁端纵向位移对中央扣的数量及自身刚度的敏感度不高。最后对矮寨大桥实测梁端位移的纵向位移响应的频谱进行了分析,与数值分析结果基本一致。To study the mechanism of longitudinal displacement at girder ends of large-span suspension bridge under moving vehicle loads,deformation characteristics of suspension bridge under non-symmetric vertical loads were analyzed based on the deflection theory.The longitudinal dynamic equation and resonance velocity of suspension bridge girder end under moving loads were derived,and the longitudinal displacement response law of suspension bridge girder end under moving loads was studied adopting equivalent longitudinal load.Taking a certain long-span suspension bridge as an example,the law and influence of its girder end longitudinal displacement under moving vertical load were studied numerically.The results showed that under moving loads,the main girder end has longitudinal forced vibration mainly with the equivalent longitudinal disturbance frequency;when load moving speed is smaller,the main girder end mainly reveals the pseudo-static effect,with increase in load moving speed,its dynamic effect is enhanced;structural damping,damper and bearing friction can suppress girder end longitudinal displacement,the influence of bearing friction on girder end longitudinal displacement can’t be ignored;setting central buckle can effectively reduce longitudinal cumulative displacement of girder end under moving vehicles,but girder end longitudinal displacement is not very sensitive to the number of central buckles and its own stiffness.Finally,the longitudinal displacement response frequency spectrum for the measured girder end of Aizhai bridge was analyzed.It was shown that the spectral analysis results basically agree well with the numerical analysis ones.

关 键 词：悬索桥 移动荷载 梁端纵向位移 共振速度 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]