Abstract：
Based on three dimensional finite element program ABAQUS, the settlement and lateral deformation of existing pile foundation with different pile-tunnel distance induced by tunnel is analyzed, and the numerical results show that: the top part of the pile foundation will move toward the tunnel while the bottom part will move toward the opposite side, thus the P-Δ effect occurring on the pile foundation; pile settlement and maximum lateral deformation are decreased with the increasing of pile-tunnel horizontal distance, and the allowable minimum pile-tunnel horizontal distance is approximate 2 times of the tunnel diameter D when the axis of the tunnel is located at the bottom of the pile foundation; additional deformation will be minished when the axis of the tunnel is above the pile base, and the and the allowable minimum pile-tunnel vertical distance is about 0.5 D when the horizontal distance of tunnel-pile is 1.5 D.
