Abstract: The deformation and the internal force distribution characteristics of the supporting structure in a deep excavation project are presented in this paper. Three-dimensional numerical simulation method was used to simulate the entire process of the excavation. Under the influence of building load and roadway vehicle load, the excavation deformation trend of the excavated area and the horizontal deformation of the supporting wall were analyzed. The variation pattern with depth, the stress characteristics of the three-layer lateral support and the underground continuous wall and the supporting effect are evaluated. The results show that the maximum deformation occurs on the loading side of the 8-story building after the excavation, and the value is about 14 cm. The depth of the building load on the deformation of excavation is about 3 times that of the loading width. The main force structure of the first layer of the transverse support is the tubular beam, the second and third layers are the main beams, and the auxiliary beams play a fixed and connecting role. The main compressive stress of the underground continuous wall is greater than that of the middle and upper parts. The maximum compressive stress is about 5MPa. The maximum bending moment of the continuous wall appears at the depth of 6m on the side of the 8-story building, and the value is about 1 600 kN·m. There are three obvious inflection points at 6m, 10m and 14m, indicating that the lateral support has a certain limiting effect on the bending of the underground continuous wall.

Key words: Deep Excavation, Excavation Deformation, Structural Internal Force, External Load, Numerical Simulation