Analysis on Characters of Cross-Fault Tunnel under Action of Earthquake

Recent earthquakes indicate that tunnels can not be considered as structures invulnerable to earthquakes, especially in areas crossing a fault. Seismic damage, such as falling, fissure and dislocation of the tunnel lining may happen at location of fault. Under the action of earthquake, two kinds of loads may occur, which are the fault movement and the function of seismic wave. In order to analyze the seismic damage to cross-fault tunnel, the seismic characters under each kind of load are studied by using finite element method. Some meaningful conclusions have been achieved. Under the condition of strike-slip fault, the stress of tunnel concentrated at the position of fault, and the stress in both active and driven plate is small. The influence degree of reverse fault is between the other two kinds of faults. By enhancing the lining materials stiffness, the displacement of tunnel decreased, but the peak acceleration and first principle stress of it increased and the position of max-displacement also changed.