Closed diaphragm wall foundation is a new type foundation which is constructed by connecting wall elements into a closed shape with structural connector. It has great stiffness and high bearing capacity. For its large soil core

there is interaction among soil core

walls and external soil. Based on lateral one-way loop load maintaining tests on three single chamber model walls with different sizes

the bearing characteristics of closed diaphragm wall foundation are studied. Base on the results of internal forces and displacements of the wall

this paper analyzes the mechanism of bearing capacity under the lateral load

the load-displacement characteristics of the wall

the distribution of the wall displacement

bending moments

shear forces and rotation of the wall along the depth. The test results can be concluded that closed diaphragm wall fails as rigid failure mode; the bending moment changes nonlinearly with the depth; the shear force reaches the maximum value at the loading point

and decreases zero at the maximum bending moment point

and changes as “belly-shaped” below the point. And the horizontal bearing capacity of closed rectangular diaphragm wall increases with the increase of the side length and depth of the wall.