ABSTRACT
Mountain tunnels are inevitable to go across active faults. The fault dislocation can result in significant damage to the tunnel structure and affects its stability and safety. This study presents a three-dimensional finite element analysis that simulates the fault dislocation by applying combined displacement loads on a surrounding rock-tunnel-fault system. The tunnel is simulated by a verified plastic damage model. The effects of different fault dislocation modes on the mechanical response of tunnels are examined. Results demonstrate that fault dislocation significantly impacts the stress and deformation of the tunnel, leading to concentrated damage and destruction in specific areas. The stress response and failure mode of the tunnel vary under different dislocation modes, with normal fault leading to primarily tensile failure, and reverse fault dislocation causing compression damage. Under strike-slip faults, shear failure is the primary damage mode.
