Study on the Seismic Response and Aseismic Measure of Fault-Crossing Tunnels under Combined Action of Fault Dislocation and Seismic Motions

Seismic investigation revealed that a fault fracture zone is one of the most vulnerable areas mountain tunnels in earthquakes. For tunnel crossing secondary fault, may be permanently dislocated by causative faults during earthquakes, making subject to combined action seismic motion and dislocation, which makes response more complicated. In order investigate fault-crossing this case explore suitability different aseismic measures, three-dimensional numerical models with widths measures were developed study. By inputting accelerogram considering permanent displacements, responses under dislocation simulated. The results showed acceleration stress tunnel-crossing narrow are larger than those wide Grouting reinforcement can reduce within while flexible joints will increase fault. tunnels, if width diameter, best measure installs grouting joints; wider 10 times reinforcement.