Numerical analysis of deformation of excavation of Foshan Dongping Plaza using edge top-down construction method

For the deformation of excavations using the edge top-down construction method, the resisting lateral force provided by the inner structure is the key factor during the construction period. Combined with a practical project, a 3D finite element model is simulated and analyzed. Considering the mechanical properties of deep soft soils, the hardening-soil (HS) model is used. The deformation, ground settlement and stress distribution of the resisting lateral walls are analyzed and compared under four cases: the inner resisting lateral walls for one, two, three rows and the top-down floors fixed support at the end. The results show that compared with those of one row of the resisting lateral walls, the horizontal displacement of diaphragm wall and the settlement of ground with two and three rows of resisting lateral walls can be reduced by approximately 20% and 30%, and they are obviously smaller in the case of the top-down floors fixed support at the end, which increases the risk of engineering. According to the calculated results, some suggestions are given to optimize the design.