中文摘要：

将轨道模拟为铺设在地基上的欧拉梁，对高速列车荷载作用下的欧拉梁动力方程进行双重傅里叶变换，得到地基振动的隐式边界条件。保留每个结点为3个自由度，通过常规u-p格式有限元推导，得到横观各向同性饱和地基有限元控制方程。分别考虑外行SH波、SV波、P波，推导相应的2．5维有限元格式的黏弹性动力边界来模拟人工截断边界。通过与已有文献的对比分析，验证本文理论及计算程序的正确性。算例分析结果表明：随着距离轨道中心距离的增加，土体振动位移减小，加速度衰减减缓；随着深度的增加，孔隙水压力减小，孔隙水压力曲线第一个拐点出现在第1，2层土的分界面上，在深度为10m处，孔隙水压力减小至0。

英文摘要：

Supposing the track as Euler beam sleeping on a saturated soil, applying double Fourier transform to equilibrium equation of the Euler beam, an implicit load equation is derived. The u-p format 2.5D finite element governing equation is derived by employing Galerkin＇s method to dynamic equation of soil in frequency domain and the boundary equation. The corresponding artificial boundary is obtained considering SH waves, SV waves and P waves respectively. The calculation program is conducted by Fortran; and the correctness is verified for the present method from the existing literature. The results show that ground vibration displacement decreases and the acceleration attenuates slowly with the increasing distance. Pore water pressure decreases with the increase of depth; and the first inflection point of pore water pressure curve appears at the interface of 1st and 2nd layered soil. When the depth increase to 10 m, the pore water pressure decrease to 0.