Seismic response of subway tunnels crossing at short distance

With urbanization and development of urban underground space the metro network is becoming ever more complicated and subway tunnels are closely located and undercrossing each other．To provide some reference for the seismic design of subway tunnel crossing at short distance, ABAQUS and time history analysis method were used to analyze the seismic response of subway tunnels crossing at different distances．When the distance between upper and lower orthogonal tunnels is less than half of the tunnel diameter, the lower tunnel has increased influence on the seismic response of the upper tunnel．Distances between the upper and lower orthogonal tunnels should be considered critically in the seismic design of metro tunnel structure．