Internal force and deformation of deep foundation pit under asymmetric water pressure

Based on the foundation pit of a subway station, the internal force and deformation of deep foundation pit under asymmetric water pressure and symmetric water pressure are comparatively analyzed by means of the two-dimensional finite element numerical method. The variation of the internal forces and deformation of supporting structures is obtained so as to provide experience and guidance for design and construction of similar projects. The results show that the supporting structures under asymmetric water pressure has some offset deformation toward the lower water pressure side, and the deformation at the higher water pressure side increases simultaneously. This deformation mode is harmful to the safety of the deep foundation pit and the environmental protection, but the asymmetric water pressure has little effect on the internal force distribution of the supporting structures. Compared with that under symmetric water pressure condition, the internal force at the higher water pressure side basically does not change, but the internal force at the lower water pressure side decreases significantly under asymmetric water pressure condition. The axial force of supporting structures reduces as the water level decreases, and the reduction basically equals to the water head difference between both sides. The consolidation settlement induced by dewatering of the late excavated soils inside the foundation pit causes the deformation of supporting structures.