中文摘要：

饱和土隧道在集中荷载作用下的隧道底面振动位移反应关系着饱和土的液化、震陷。根据饱和土中方形隧道的断面特征，采用两相饱和介质边界元法Green函数以及推导出的Lamb积分方程，计算出机车的集中振动引起的隧道底面振动反应表达式。结合具体算例，数值计算后表明结果可信。

英文摘要：

Saturated soil under a concentrated dynamic load in a tunnel will cause vibration displacements, which concerns the liquefaction, and shaked subsidence. The paper will be based on the tunnel＇s section feature located in saturation soil, adopting a two-phase saturated medium＇s Green function in BEM and Lamb integral equation to infer from Betti theorem to figure out the displacement function of the underside in the tunnel arose by vehicle-engine vibrations. Combined with the exact example, the value after being calculated indicates that the result is reliable.