Numerical Analysis of the Influence of Tunnel Undercrossing Buildings on Pile Foundation

The construction of subways inevitably involves underpass buildings. To ensure the stability of buildings, taking the undercrossing buildings by the Chongqing Rail Transit Line 5 branch as an example. A three-dimensional numerical model of the pile foundation and tunnel was established using FLAC3D. The simulation results show: In the 1-1 profile, the maximum displacement is about 2.28 mm, and the displacement gradually decreases along the top of the tunnel. The maximum displacement in the profile is about 2.28 mm, and the displacement at the bottom of the pile foundation is about 0.3 mm.In the 2-2 profile, the maximum displacement is about 2.27 mm. At the building's pile foundation, the displacement is about 0.2 mm, and at the bottom of the pile foundation, the displacement is about 0.3 mm.In the 3-3 profile, the maximum displacement is 2.26 mm, located at the crown of the tunnel. The displacement at the building's pile foundation is less than 0.2 mm. Based on the analysis of the data from the FLAC3D three-dimensional numerical simulation results, The excavation of the tunnel has a minimal impact on the pile foundations of the aforementioned buildings, and the safety and stability of the buildings are not affected.