NUMERICAL SIMULATION OF THE INFLUENCE OF SID FOUNDATION PIT EXCAVATION ON ADJACENT SUBWAY STRUCTURE
Taking the excavation of the side foundation pit of a subway transfer station as the case,we study the lon-gitudinal deformation response of the tunnel structure under eccentric unloading.Based on the small strain soil stiff-ness model,a three-dimensional complex model of the station-tunnel-foundation pit was established considering the contribution of the station to the overall stiffness of the tunnel structure.According to the practical excavation process,the construction of the side foundation pit partition is simulated,and the longitudinal deformation results of the tunnel structure are obtained.The influence of the location relationship between the pit and the tunnel on the lon-gitudinal deformation of the tunnel is analyzed.When the distance between the pit and the tunnel is more than twice the excavation depth,the tunnel deformation is mainly horizontal displacement,and the constraint effectiveness of the corner point of the enclosure structure on the longitudinal deformation of the tunnel is gradually weakened with the increase of the unloading degree.
side foundation pitlongitudinal deformationhorizontal displacementcorner constraint