Abstract：
Covered excavation top-down construction method is an important method for construction of large-scale extra-deep foundation pit. After simulative calculation by ABAQUS software and practical application of two different excavation methods, it is determined to adopt long linear underground diaphragm wall supporting system and to excavate from both ends of the diaphragm wall towards the middle after construction by basin excavation method at early period gets close to the wall. This method can give full play to its early space effect, shorten the limitation effect of underground diaphragm wall and minimize the lateral deformation.
