不同车载工况下桥梁振动响应试验

Experiment of Vibration Response of Bridges under Different Vehicle Loading Conditions

基于梁的横向振动理论,利用奇异函数建立移动车载作用下单跨简支梁的振动响应方程,利用Mathcad软件求解得到不同车载工况下桥梁振动的位移及加速度响应。以校内双车道玉泉桥为测试对象,在4个截面布设双排传感器,设计单一车载、同向双车载、相向双车载3种工况,每种工况设置4级车速,利用无线遥测动态应变测试分析系统采集各次试验中桥梁的加速度响应,分析车载工况、车载速度对桥梁各截面加速度峰值的影响。研究表明:同重量双车载同向运行时的实测振动响应小于单一车载作用下响应的2倍;车速相同时,3种工况中单一车载作用下振动加速度峰值最小;对于桥东2个截面,车速较小时,双车同向比双车相向时梁的加速度峰值高;而在车速较大时,情况则相反;对于桥西2个截面,双车同向均比双车相向时的加速度峰值高;速度较低时,3种工况下各截面的加速度峰值相差不大,而在速度较高时,3种工况下桥东的A截面的加速度峰值最大,桥西的D截面的加速度峰值最小。

Based on the transverse vibration theory of beams, the singular function is used to establish the vibration response equation of the single-span simply supported beam bridge under the action of vehicles, and the Mathcad software is used to obtain the displacement and acceleration response curves of the bridge under different vehicle loading conditions. The dual-lane Yuquan Bridge is taken as the test object, in which double rows of sensor in four sections axe arranged. And the three working conditions of single vehicle, two vehicles traveling in the same directions mad two vehicles traveling in opposite directions, are considered with 4 operation speeds. The acceleration response of the bridge in each experiment is collected by using the wireless telemetry dynamic strain test analysis system, and the influence of vehicle working condition and vehicle speed on the peak acceleration of bridge＇ s sections axe analyzed. The research suggests that： （1） Based on the result of the actual measurement, the vibration response of the bridge when two vehicles with same weight driving in the same direction is less than twice that of the single vehicle; （2） At the same speed, the peak of vibration acceleration under single vehicle working condition is the smallest among the three working conditions; （3） For the two sections on the east side of the bridge, when the vehicle＇ s speed is low, the acceleration peak of the bridge is higher for the condition that the two cars driving in the same direction than that for the two cars driving in the opposite direction; At the high speed, the conclusion is reversed; （4） For the two sections on the west side of the bridge, at the four different speeds for the test, the acceleration peaks of the bridge for the condition that the two cars driving in the same direction are all higher than that for the two cars driving in the opposite directions; （5） When the speed is low, the acceleration peaks of each section under the three conditions are not much different; However, when the speed is high, the acceleration peaks of the section A on the east side of the bridge under the three working conditions axe the largest, and the smallest for the section D on the west side of the bridge.