上海长江大桥车桥系统节段模型涡激共振试验研究  

Sectional model test study on vortex-excited resonance of vehicle-bridge system of Shanghai Bridge over Yangtse River

作　　者：周立[1] 葛耀君[1] 

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《土木工程学报》2007年第8期61-66,共6页China Civil Engineering Journal

基　　金：国家自然科学基金重点项目(No.50538050)

摘　　要：涡激共振通常都在低风速发生,且涡激共振对断面形式的微小变化很敏感,因此有必要研究车辆对车桥系统涡激共振性能的影响。以上海长江大桥为背景,在同济大学土木工程防灾国家重点实验室TJ-1边界层风洞中进行了1∶60缩尺模型试验,开展了桥面无车状态、桥面有车状态下的两种断面形式以及0°、+3°和-3°三种风攻角共6个试验工况节段模型涡激共振试验研究,并将模型试验结果经过振型修正换算到实桥。试验结果表明:桥面有车状态下的竖弯涡振和扭转涡振中分别伴有相同频率的扭转振动和竖弯振动;桥面有车状态的竖弯涡振和扭转涡振幅值明显比桥面无车状态大;桥面有车状态下的涡振锁定风速区间比桥面无车状态下提前。可见车辆明显改变了主梁的气动外形,且无论从振幅还是振动形态方面考虑,车辆对车桥系统的涡激共振影响是不可忽视的。It is necessary to study how vehicles influence the vortex-excited resonance of vehicle-bridge systems, because lock-in wind speed is low and vortex-excited resonance is sensitive to any change of main girder sections. Based on the Shanghai Bridge over Yangtse River, the vortex-excited resonance of a 1：60 scale sectional model was tested in a TJ-1 wind tunnel, without or with vehicles at the attack angle of 0 （, ＋3 （ and -3 （, respectively. The conversion relationships between the resonant amplitudes of the sectional model and that of the prototype bridge were also established by mode shape correction. The result indicates that： a） for the bridge with vehicles, the vertical vortex-excited resonance is accompanied by torsion vibration with the same frequency, and vice versa, b） the amplitude of vortex-excited resonance of the bridge with vehicles is much larger than that of the bridge without vehicles, and e） the lock-in wind speed of the vortex-excited resonance becomes smaller due to the disturbance of vehicles. It is obvious that vehicles bring about changes in the aerodynamic shape of the main girder. Therefore, the influence of vehicles on vortex-excited resonance performance of vehicle-bridge systems, in terms of both amplitude and mode, should not be ignored.

关 键 词：车桥系统 节段模型 涡激共振 风洞试验 振型修正 

分 类 号：U441.2[建筑科学—桥梁与隧道工程]