Abstract: Based on Biot’s theory and the minimum potential energy principle as well as the thin plate theory, the superstructure, raft and soil are assumed to be whole system according to the substructure method. The system must satisfy the continuity conditions at the interface between the superstructure, raft and soil surface. Considering the compatibility condition that the vertical displacement of the interface between the raft and the saturated soil should be equal, the integral equation accounting for the vertical coupling of the superstructure-raft system with the saturated soil subjected to a moving load is constructed. Using the numerical inverse transform technique, the forces and displacements of the superstructure, plate and saturated soil at any time are obtained. Some numerical results are presented to demonstrate the capacity of the proposed model. Numerical results show that the horizontal displacements and vertical displacements of each floor of the superstructure increase with increasing velocities of moving load. The vertical displacements in each floor have small change. Also, for a lower moving velocity, the curve of the horizontal displacements changes smoothly with the superstructure height increasing. When higher moving velocity, the curve of the horizontal displacements changes obviously with superstructure height increasing.

Key words: moving loads, saturated soil, superstructure, thin plate theory, substructure method, integral equation