Abstract:For the excavation in the soft soil area, it is very important to control the deformation. In this paper, the finite element analysis of the pipe gallery excavation with flexible retaining structure in Nansha, Guangzhou is carried out. The deformation characteristics of the excavation during the excavation process are obtained. When excavating to the bottom, the maximum horizontal displacement value of the retaining structure reaches 31.92mm, the maximum value of surface settlement and basal heave is 22.26mm and 54.81mm, the stability calculation result is 2.2, whose deformation and stability meet the requirements of the specification. Then, under the two conditions of critical instability state and stability meeting the specification for 6 different excavation sections, the maximum deformation value of the retaining structure horizontal deformation, surface settlement and basal heave accounted for the percentage of the excavation depth. It is recommended to use the average of the calculated results as a reference value for the control value. Under the critical instability state, the reference values ??for the horizontal deformation control of the retaining structure with the design safety level two and three are 2.62%H and 3.24%H, respectively. When the stability of the excavation meets the requirements of the specification, the reference values ??for the horizontal deformation control of the retaining structure with the design safety level two and three are 0.8%H and 0.93%H, respectively.