A study of the effects of degree of saturation on the nearly saturated ground dynamic response caused by high-speed trains moving is presented. The soil medium is assumed as an isotropic nearly saturated half space. Dynamic governing equations of nearly saturated soil are derived based on Biot's theory, and 2.5 dimensional element equations are developed through Fourier transform. The exactly numerical solutions in time domain of the nearly saturated ground vibration responses are obtained. The results show that the peak values of ground acceleration amplitudes increase about 1.46 times when S_r decreases from 100% to 95%. The value of pore pressure decreases from 6.4 kPa to 0.3 kPa with S_r decreasing from 100% to 95%. A highly errors will exist in the calculation of ground vibrations when the nearly saturated medium is simply regard as saturated.

中文翻译：

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列车在接近饱和地面上行驶时引起的地面振动的探索

提出了饱和度对高速列车行驶引起的近饱和地面动力响应影响的研究。假定土壤介质为各向同性的接近饱和的半空间。基于Biot理论推导了近饱和土的动力控制方程，并通过傅立叶变换建立了2.5维单元方程。得到了近饱和地面振动响应的时域精确数值解。结果表明，当S _r从100％降低到95％时，地面加速度振幅的峰值增加约1.46倍。随S _r孔隙压力值从6.4 kPa降低到0.3 kPa从100％降至95％。当将几乎饱和的介质简单地视为饱和时，在计算地面振动时将存在很大的误差。