列车通过城市轨道交通高架桥对地面振动影响研究

Study on influence of ground vibration when train passing through urban rail transit viaduct

为探究列车通过城市轨道交通高架桥时地面的振动特性及振动传递特性,以某一城市轨道交通高架桥为研究对象,对距离桥墩不同距离处同时进行振动测试,对结果进行频域特性分析,然后采用线性计权及Z计权进行1/3倍频程特性分析,并分析了分别采用这两种计权方式时,特征频率下振动的传递特性,最后进行了等效连续Z振级传递特性分析。结果表明:列车通过城市轨道交通高架桥时,地面的振动加速度主要分布在0~200 Hz频率范围内,且振动加速度峰值主要分布在60~80 Hz频率范围内;在线性计权下,地面的振动加速度级全局峰值均出现在频率63 Hz处,局部峰值均出现在频率为4 Hz处;在Z计权下,地面的振动加速度级全局峰值均出现在50~63 Hz范围内,局部峰值均出现在频率为4 Hz处;振动由桥墩底部沿地面传递过程中,随着与轨道中心线距离的增加,地面振动加速度级不断减小,且衰减速度随距轨道中心线距离的增大而减小。

In order to explore the vibration characteristics and vibration transm ission characteristics when the train passing through the viaduct of urban rail transit,taking an urban rail transit viaduct as the research object,the vibration test is carried out at different distances from the pier.The test results are analyzed in frequency domain.Then,the 1/3 octave are analyzed by using linear weighting and Z weighting,and the transmission characteristics of vibration under characteristic frequency are analyzed w hen two w eights are adopted respectively.Finally,the transm ission characteristics of equivalent continuous Z vibration level are analyzed.The results show that w hen the train passes through the urban rail transit viaduct,the vibration acceleration of the ground is mainly distributed in the 0~200Hz frequency ran g e,and the peak value of vibration acceleration is m ainly distributed in the frequency range of 60~80Hz.Under the linear weighting,the global peak of the vibration acceleration level of the ground appears at the frequency of 63H z,and the local peak appears at the frequency of 4Hz.Under the Z weighting,the global peak value of the vibration acceleration level of the ground appears in the range of 50~63Hz,and the local peak values appear at the frequency of 4Hz.With the increase of the distance from the center line of the track,the acceleration level of the ground vibration decreases with the increase of the distance from the center of the pier to the ground,and the attenuation rate decreases with the increase of the distance from the center line of the track.