“房桥合一”轨道层结构车致振动响应测试研究

Field Measurement and Analysis of Train-Induced Vibration of "Building-Bridge Integration" Structure

为研究"房桥合一"轨道层结构车致振动特性与传播规律,选择天津西站轨道层结构,测试客、货列车通过时的轨道层结构振动加速度响应。16种工况共128组数据的分析结果表明:在列车低速通过时,"房桥合一"轨道层结构的加速度振级范围为83～113dB;同一测点在相同振源距离、相同车型下,其振级随车速的增加而增大;在相同车速和车型下,测点的振级随距振源距离的增加而呈非线性减小,减小程度随距振源距离增加而降低。车速对"房桥合一"轨道层结构的主要车致振动响应频率的影响不大;距振源越近,频谱峰值越大;车速越高,频谱峰值越大。客、货列车对"房桥合一"轨道层结构的激振频率不同;货车对结构有低频激励影响,且高频激振不稳定;客车高频激励较为稳定。采用点振源函数拟合"房桥合一"轨道层结构的车致振动响应,获得了可以表征"房桥合一"轨道层结构车致振动传播规律的振动衰减曲线。

To study the characteristics and propagation laws of train-induced vibrations on the track level of ＂building-bridge integration＂ structure,the track level structure of Tianjin West Railway Station was chosen to test the vibration acceleration responses when both passenger trains and freight trains passed.128 groups of data under 16 working conditions were analyzed.Results show that,the acceleration vibration on the track level of ＂building-bridge integration＂ structure ranges from 83 to 113 dB when trains passing at low speed.The vibration level increases with train speed under the condition of the same measure point,vibration source distance and train type.The vibration level of the measure point decreases non-linearly with the increase of the distance away from the vibration source under the same train speed and train type,and the decrease extent reduces with the increase of the distance away from the vibration source.The main train-induced vibration response frequency of ＂building-bridge integration＂ structures is little impacted by train speed.The shorter distance away from vibration source and the higher train speed is the larger frequency spectrum peak value will be.There are differences in the excited frequency of ＂building-bridge integration＂ structures induced by passenger and freight trains.The vibration induced by freight train has a low frequency excitation to the structure and high frequency excitation is unstable,while the high frequency excitation of the vibration induced by passenger train is stable.Point vibration function is used to fit the train-induced vibration response of ＂building-bridge integration＂ structure,and the vibration damping curve which can characterize the propagation laws of train-induced vibration in ＂building-bridge integration＂ structures was got.