无砟轨动车组运行激励场地振动谱分析

Spectral analysis of field vibration induced by CRH2 operation in truck on railway without ballast

为研究CRH2动车组在无砟轨道段运行引起的场地加速度振动的频谱特性，本文对我国首条无砟轨道段（渝遂铁路二岩隧道一湾里头隧道段）动车组运行时的场地振动进行了现场实测；对实测竖向振动加速度时程进行1／3倍频谱分析表明：地面竖向振动加速度随着与振源距离的增大而明显衰减，随车速增大场地振动强度增强；应用正交HHT变换，对加速度时程进行了Hilbert谱分析，获得了地面竖向振动加速度的主频为10—120Hz、振动传播高频成分衰减较快等频谱特性；最后，将Hilbert边际谱与傅里叶谱进行了对比分析，得到了两种方法分析振动信号频谱特性表现出的差异性。

In order to study the frequency spectrum characteristics of the field vibration acceleration induced by impetus locomotive CRH2 operation in the truck on railway without ballast, field vibration meastrrement was performed on the Suining-Chongqing railway without ballast between Er-Yan Tunnel to Wan-Litou Tunnel. Through one third octave spectrum analysis of vibration acceleration time-history data, it can be sure that ground vibration acceleration obviously decreases with the increase of distance to the central railway line, and the vibration acceleration increases with the train speed increase. Thus, based on the orthogonal Hilhert-Huang transformation（HHT） of the spectrum analysis vibration acceleration time-history , the frequency spectrum characteristics are as follows： the vibration dominant frequency distribution is 10 Hz to 120 Hz; attenuation of high-frequency vibration is faster than that of low-frequency vibration. Then, by the comparative analysis of marginal Hilbert spectrum and Fourier spectrum, the differences of the frequency distributions of the ground vibrations are revealed.