大跨径人行钢悬索桥动力特性研究  

Research on the Dynamic Characteristics of Large Span Steel Suspension Footbridge

作　　者：彭伟 Peng Wei(Chongqing Anji Construction ＆ Reinforcement Co.,Ltd.,Chongqing 401120,China;State Key Laboratory of Bridge Engineering Structure Dynamics,Chongqing CommunicationResearch ＆ Design Institute Co.,Ltd.,China Merchants Group,Chongqing 400067,China)

机构地区：[1]重庆安济建设加固工程有限责任公司,重庆401120 [2]招商局重庆交通科研设计院有限公司桥梁工程结构动力学国家重点实验室,重庆400067

出　　处：《防灾科技学院学报》2018年第2期21-26,共6页Journal of Institute of Disaster Prevention

基　　金：重庆市教委科学技术研究项目(KJ1401323)

摘　　要：随着跨径增大,人行钢悬索桥的宽跨比与高跨比明显减小,结构整体刚度较低,行人过桥时的结构振动问题较突出。以国内某在役人行钢悬索桥为研究对象,通过数值计算与实桥动力测试研究了结构自振频率、振型与阻尼比等动力特性参数,参考国内外有关规范资料评价了结构自振频率。结果表明,该桥低频范围的横向、竖向振动模态较密集,按脉动法实测频率与计算频率的比值为1.48~2.93,由于结构竖向与横向自振基频均小于1Hz,对行人激励较敏感,建议根据桥梁现状对上部结构进行适当改造以提高结构刚度或进行减振设计以改善结构动力性能。For steel suspension footbridge,the width-span ratio and depth-span ratio are obviously decreased and structural integral stiffness is thus reduced with the growth of span,which leads to the prominent problem of structural vibration when pedestrians cross bridge. Taking a domestic suspension footbridge in service as the subject,we research ed the dynamic characteristic parameters including natural vibration frequencies,modes of vibration and damping ratios by numerical calculation and field dynamic test,and assessed structural natural vibration frequencies according to the relevant specifications at home and abroad. As the results show,close vibration modes with low frequencies in vertical and transverse directions appear in the study bridge,and the ratio of natural vibration frequencies between measurement by pulsating method and calculation is 1. 48 - 2. 93. Due to structural fundamental frequencies of vibration is less than 1 Hz in vertical and transverse directions,steel suspension footbridges are sensitive to pedestrian motivation. So it is suggested that relevant improvement measures are necessary based on bridge actuality,including increasing structural stiffness by appropriately modifying the superstructure or improving bridge dynamic performance by vibration reduction design.

关 键 词：钢结构 人行悬索桥 动力特性 环境激励 减振 

分 类 号：U448.25[建筑科学—桥梁与隧道工程] TU311.3[交通运输工程—道路与铁道工程]