Tliroc-Dimensional Finite Element Analysis of Influence of Foundation Pit Excavation on the Safety of Adjacent Subway Tunnel

摘要

Combined with the surrounding environment and supporting design scheme of deep foundation pit project, three-dimensional finite element numerical simulation and analysis of the influence of excavation, and support on adjacent subway tunnel are carried out by using MIDAS software. Some deformation is calculated produced by the construction of pit foundation, including the deformation of the retaining structure and supporting structure of pit foundation, the lining structure of adjacent subway tunnel. The results are shown as follows: ground disturbance will be produced by the excavation and supporting construction of pit foundation. Therefore, the settlement and deformation of adjacent subway tunnel structure will be also produced. According to actual construction conditions, under normal operation conditions for the supporting structure, the maximum horizontal displacement of 4.8 mm and the maximum vertical deformation of 0.12 mm for the adjacent subway tunnel structure are produced by the construction of pit foundation. The above deformation meets the requirements of rail transit deformation of adjacent subway tunnel operation track, and which has some influence on the safe operation of adjacent subway tunnel. The above research results have important practical significance to the accurate prediction on the influence of foundation pit construction on the existing subway structure, also have important practical significance to guarantee for the safe operation of subway structure.