Abstract: With the continuous construction of newly planned subway lines, the deformation control requirements for adjacent subway stations in the construction of deep excavations for buildings are becoming more stringent. The design of a deep excavation adjacent to a subway station in Huangpu District, Guangzhou, is presented in this paper. A three-dimensional model is established to numerically simulate and analyze the excavation of the deep excavation site under multiple working conditions. The analysis results show that the most unfavorable working condition is when the excavation reaches the bottom (before replacing the support). The rigidity of the supporting structure in the northeast and southeast corners of the excavation is relatively weak, and the supporting system is more stable after strengthening with the addition of large triangular corner braces (beam slab combination). Except for the construction defects of the water cut-off curtain caused by the old foundation obstacles on the site, which resulted in the measured values of the WY7 and ZC6 monitoring points on the east side being greater than the calculated values, the calculated values of the horizontal displacement of the top of excavation and the internal support axial force of the other monitoring points are close to the measured values and less than the design control values. The monitoring data of the station tunnel during subway operation also indicates that the tunnel structure is in a safe state.

Key words: Deep Excavation, Internal Support, Numerical Simulation, Excavation Monitoring