Numerical Simulation and Field Monitoring Analysis for Deep Foundation Pit Construction of Subway Station

To investigate the effect of deep foundation pit excavation on the stability of retaining structure, a subway station in the city of Jinan was selected as a project, and a FLAC3D-based three dimensional model was developed for numerical simulation. The horizontal displacement of the retaining structure, the axial force of the support, and the vertical displacement of the column were studied and compared to the collected data from the field. The findings indicate that when the foundation pit is excavated, the maximum deformation of the retaining structure progressively decreases from the top, the distortion of the retaining structure gradually rises, and the final maximum deformation is around 17 meters deep. In each layer of support, the largest axial force support is located in the first reinforced concrete support; the uplift of the pit bottom caused by soil unloading plays a primary role in the vertical displacement of the column, and the column exhibits an upward trend under all construction conditions. When compared to the measured data, the generated findings are comparable and the fluctuation trend is extremely consistent. The findings of this article may give technical direction for the development of subway stations with a comparable engineering basis.