An Automation Computation Algorithm Calculation Method of Soil Rebound at the Bottom of Foundation Pit Considering the Engineering Piles

Accurate prediction of excavation-induced soil rebound is critical for intelligent foundation pit construction. The existence of engineering piles in the foundation pit will affect soil rebound at the bottom of the pit caused by excavation. Based on the layer-wise summation method, the Mindlin solution and the existing calculation methods of pile-soil displacement, the rebound deformation of the soil at the bottom of the pit caused by the excavation unloading of the foundation pit was studied and an automated computation algorithm for calculating soil rebound under the existence of an engineering pile was proposed. Finally, the calculation results of the proposed method and the finite element simulation results were compared and analyzed with an example of engineering. The results show that for the rebound curve of the foundation pit bottom, when there are no engineering piles, it presents a smooth ‘convex’ shape; when engineering piles exist, it presents a fluctuant ‘wave’ shape. The rebound of the soil around the engineering piles is significantly lower than that of the neighboring soil, with the smallest drop in the edge area of the foundation pit and the largest drop in the central area, and the maximum reduced rebound can reach about 20% at most. The ability of piles to limit soil rebound is greatly related to the pile spacing and pile diameter. It is necessary to correctly consider the existence of engineering piles in the rebound calculation of the soil at the bottom of the foundation pit, and the results obtained by the proposed method in the paper are in good agreement with the simulated rebound values. The method proposed in this paper can effectively predict the rebound deformation of the foundation pit.