Contact element is used to simulate the nonlinear behavior of interaction of diaphragm wall and base. Duncan-Chang E-B criterion is used as constitutions relation of base and dam to represent nonlinear and inelastic characteristics. FEM is used to calculate the stress and deform ation of dam

base and diaphragm wall. The result shows that the stress and strain of dam depend on the selection of dam. The characteristic of diaphragm wall also affects the stress and strain of dam in some regions. The stiffness of diaphragm wall is a key factor in the stress and strain in dam and diaphragm wall. If the stiffness of wall is large

the vertical displace is affected obviously. And the danger location is at the bottom of the diaphragm wall. Besides

the ability of adapting to deformation is high. But the displacement is large. The danger location is at the bottom of dam.