In foundation pit engineering design, the seepage‐induced impact of groundwater is often oversimplified when calculating the deformation of the retaining structure and the surrounding soil caused by excavation. Moreover, the coupled interaction between groundwater and soil is neglected, causing simulated conditions to deviate from actual site conditions. Based on a deep‐excavation project for a subway station in Taiyuan, this study uses PLAXIS 3D finite element software to simulate the entire process of dewatering and excavation, with a focus on the seepage effect induced by dewatering. After validating the proposed finite element model using field monitoring data, the deformation patterns of the retaining structure, the soil outside the pit, and the soil at the pit bottom during construction are analyzed. The findings are as follows: (1) simulation results closely match the field monitoring data, confirming the model’s reliability; (2) as excavation progresses, the horizontal deformation curve of the retaining structure changes from a cantilever shape to an arch shape, with the maximum deformation consistently occurring near the excavation face due to the combined effects of excavation and groundwater seepage; and (3) the location of the maximum ground settlement outside the pit gradually moves away from the pit as excavation advances. Substantial seepage caused by dewatering contributes to >70% of the total ground settlement outside the pit. Furthermore, a simplified formula for estimating ground settlement induced by dewatering seepage is proposed. This study thus provides data support and reference for engineering design and construction in similar soil conditions.
Li et al. (Thu,) studied this question.