Abstract: During the construction of large and deep foundation, the soils may move into the excavation beneath the diaphragm wall. This phenomenon closely relates with the influence on the surroundings. The soils beneath the diaphragm wall are modeled, and a method is deduced for calculating the soil displacement considering the excavation area, excavation depth, length of diaphragm wall and soil properties. A comparison between the analytical results and the monitoring data as well as the parameter studies on the soil displacements are then carried out.