Analysis of Stress Path in the Whole Process of Foundation Pit Excavation and Heavy Lifting

Abstract

Based on a foundation pit in Jinan City, this paper uses ABAQUS to conduct numerical simulations based on actual construction on site. Considering the rotation of the main stress axis, the corresponding stress path and discharge law are obtained in different affecting areas. The results show that whether inside or outside the pit, the horizontal and vertical stresses decrease with the excavation of the foundation pit, but the amount of soil unloading inside the pit is much greater than outside the pit; the passive zone in the pit keeps decreasing, and keeps increasing. The range of rotation angle of large principal stress is 0∼89.39°, the transition zone outside the pit and the active zone keep decreasing, while is almost unchanged, the change range is 0∼44.78°, and all rotate clockwise. When a crane load is applied to the side of the pit, it will have a greater impact on the soil elements in the active zone directly below the load outside the pit. The principal stress rotation angle will rotate counterclockwise, which is about 1/3 of the final deflection angle. The impact is relatively small.