Abstract: To ensure the safety of the surrounding environment in the excavation of foundation pits, taking the excavation of a deep foundation pit at a Xi'an subway station as an example, ABAQUS was used to establish a three-dimensional model to simulate the impact of excavation on the surrounding surface settlement and the deformation of the retaining structure. This study focused on the distribution of the surrounding surface settlement and the deformation of the retaining structure and compared the simulation results with actual monitoring data to guide site surface settlement monitoring. Analysis results show that the measured value is larger than the simulated value, but the change trend is the same. In the process of foundation pit excavation, the maximum ground settlement occurs at 11 m from the edge of the foundation pit, the maximum value being 3.29 mm; the horizontal deformation curve of the retaining structure along the excavation depth is a parabola, the maximum horizontal displacement occurs at 1/2 of the maximum excavation depth of the foundation pit, and the value is 11.05 mm. The ground settlement within 0~25 m from the long edge and 0~22 m from the short edge of the foundation pit is the largest, which should be focused on in construction monitoring.

Key words: deep foundation pit, surface settlement; numerical analysis, ABAQUS