环境激励下斜拉桥拉索的振动观测研究  

RESPONSE CHARACTERISTICS OF STAY CABLE UNDER AMBIENT EXCITATION

作　　者：王修勇[1] 陈政清[2] 倪一清[3] 胡建华[2] 

机构地区：[1]湖南科技大学土木工程学院,湘潭411201 [2]湖南大学土木工程学院,长沙410083 [3]香港理工大学土木与结构工程系

出　　处：《振动与冲击》2006年第2期138-144,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金资助项目(50578063;50178013);湖南省教育厅重点项目(04A014)资助

摘　　要：斜拉桥拉索在风、风雨组合、交通荷载等环境激励下发生大幅振动,这种振动对拉索造成极不利的影响。为了研究拉索的振动机理和响应特征,在岳阳洞庭湖大桥建立了包括风速仪、雨量计、加速度传感器组成的拉索振动观测系统,进行了多次长时间观测。根据观测记录,采用时频分析、统计技术,对拉索涡振、风雨振、交通引起的振动等响应特征、振动与环境激励的关系、振动的模态参与性、索力变化等进行了研究,得到了一些对认识拉索振动机理、并进一步控制拉索振动具有意义的结果。The cable vibration on the cable-stayed bridge can easily be excited by wind, combination of wind and rain, traffic loads and so on. To investigate the excitation mechanism and response characteristics of cable vibration under ambient excitation, the field measurements were carried out on the Dongting Lake Bridge, which is the first three towers, pre-stress concrete cable-stay bridge in China mainland. This measurement system consists of anemometers, rain gauge and accelerometers. Based on the measured records and time-frequency analysis technique, the relationships of cable acceleration responses under the vortex shedding and the wind-rain induced vibration versus ambient excitation such as wind and rain are investigated,and the response characteristics of cable vibration,which include the dominant frequency,modal participation,dynamic displacement and tension increment under ambient excitation,also are presented.

关 键 词：斜拉桥 拉索振动 现场观测 时频分析 响应特征 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]