Abstract: The grid diaphragm wall is constructed by continuously sinking the steel forms into the soil, placing the reinforcement bars and concreting the grid. This new type of wall can serve as the supporting structure during the deep excavation and also as the exterior wall of the future basement. The grid diaphragm wall combines the functions of both supporting and the structural walls. This paper presents the evaluation results of this wall in various phases: during the supporting in deep excavation, immediately after construction and operation. The stress distributions in the wall at various stages are analyzed. The connection joint and seepage cutoff details are also presented. The results show that the active earth pressures during the construction was translated into atrest earth pressure in the operation and the groundwater is restored to the static water table. The moment connectors welding connections can be used at connections between wall and floor (bottom slab), wall and beam so that the reliability of these connections can be improved. For the body of the diaphragm wall, wall and beam connections, wall and bottom slab joints, seepage resistant concrete, shear stiffeners and seepage cutoff steel plates can be applied in combination with seepage prevent materials of paint. Other seepage cutoff measures such as, expansive rubber seepage stop strips and water based epoxy grouting, can also be applied. The above results can provide technical references for the future design and construction of the grid diaphragm walls.

Key words: Grid Diaphragm Walls, Dual Purpose Diaphragm Walls, Design Methods, Joint Details, Seepage Cut-off Measures