为研究场地振动加速度衰减特性，对我国首条无碴轨道试验段—渝遂铁路的CRH2动车组运行的场地振动进行了实测。基于最小二乘法，拟合了场地竖向加速度振级的一阶指数和二次多项式衰减经验公式后分析表明：一阶指数函数衰减模型更符合实际。应用正交经验模式分解法和Hilbert变换对场地竖向振动加速度信号进行频谱分析，得到了振动信号的Hilbert边际谱；对比分析表明： Hilbert边际谱较Fourier谱能更好地反映动车组引起的场地振动信号的频谱特性。

In order to study the vertical acceleration decay laws of ground vibration, the field vibration induced by impetus locomotive CRH2 were measured on the SuiYu ballastless truck. Through establishing the empirical formula of vertical acceleration vibration level decay laws on the basis of least-squares criterion , the analysis shows that the first-order exponential function is better than quadratic polynomial function in the fitting the experiment data. Based on the EMD and HHT, Comparative analysis shows that using Hilbert spectrum to study on the vibration is more suitable for than using that of Fourier spectrum