Analysis of the influence of super large area and super deep foundation pit excavation construction on surrounding subways

Abstract

The shortest distance from the deep foundation pit envelope of the project to the subway station building is only 7.7 meters, and the deepest excavation depth of the foundation pit is about 24 meters. The surrounding environment of the foundation pit is complex, involving many buildings, the construction is difficult, and there is a great risk of construction safety. The effective control of the structural deformation of the existing subway station is the key to selecting the underground enclosure structure and construction process of the surrounding post-construction projects. Combined with the actual situation of the project, the three-dimensional numerical analysis method is used to analyze the impact of the construction of the foundation pit of the building on its adjacent structures in detail, and the relevant treatment measures are proposed. The research shows that the unloading effect caused by the large-scale excavation causes the soil outside the pit to move towards the inside of the pit. Under the influence of the soil deformation transfer effect, the Beiguan Station of the R1 line subway produces certain rebound, settlement and horizontal displacement, but the values of each deformation index are within the deformation control standard, the numerical analysis considering the influence of small soil strain can better reflect the influence of foundation pit excavation on the displacement, deformation and internal force of the existing structure. It can better match the actual engineering experience.