超宽加劲梁自锚式悬索桥动力特性敏感性分析  

Sensitivity analysis on dynamic characteristics of self-anchored suspension bridge with super-wide girder

作　　者：夏志远[1] 李爱群[1,2] 李建慧[3] 端茂军[3] 

机构地区：[1]东南大学土木工程学院,南京210096 [2]北京建筑大学,北京100044 [3]南京林业大学土木工程学院,南京210037

出　　处：《东南大学学报（自然科学版）》2016年第2期360-364,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51278104);高等学校博士学科点专项科研基金资助项目(20133204120015);江苏省交通运输科学研究计划资助项目(2011Y03);江苏省高校自然科学基金资助项目(12KJB560003);江苏高校优势学科建设工程资助项目(CE02-1-35)

摘　　要：为研究超宽混凝土加劲梁自锚式悬索桥动力特性对周边环境的敏感性,采用非线性有限元与子空间迭代相结合的方法,分析恒载集度、环境温度及支座沉降等作用对该类桥梁动力特性的影响.结果表明,成桥状态下结构基频为0.674 Hz,竖向振型起主导作用,但由于加劲梁纵向约束较大,纵飘振型出现较晚;而超宽截面影响结构扭转刚度,扭转振型出现较早,且前若干阶振型出现振型耦合,分析中应考虑加劲梁超宽对自身受力行为的影响.结构自振频率对恒载集度的变化较为敏感,对支座沉降的敏感度则较低;加劲梁竖弯频率对温度变化较为敏感,横向振动相关频率对温度变化敏感度较低.建议在对结构进行动力特性现场试验时,应充分考虑结构恒载集度和环境温度对测试结果的影响.To study the sensitivity of the dynamic characteristic of self-anchored suspension bridges with super-wide concrete girders to around circumstances,the influences of the dead load intensity,the environmental temperature,and the support subsidence on the dynamic characteristic were analyzed by using the method combining nonlinear finite element and subspace iteration. The results showthat the first-order frequency is 0. 674 Hz in the finished state and the vertical vibration mode plays a leading role,but the longitudinal floating mode appears late because of the large constraints to girders in the direction. Due to the influence of the super-wide section on the torsion rigid which should be taken into account in the following analysis,the torsion mode emerges early with mode coupling. All structural frequencies are sensitive to the dead load intensity but not to the support subsidence. The frequencies of the vertical bending of the girder are sensitive to the temperature,but those related to transverse vibration are not. It is suggested that the effects of the dead load intensity and the environmental temperature should be considered in field tests of dynamic characteristics.

关 键 词：自锚式悬索桥 动力特性 子空间迭代法 敏感性分析 超宽截面 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]