oa Mountain Tunnels Performance in the 1995 Hyogoken-Nanbu Earthquake

At least one hundred and more mountain tunnels were in service in and around the disaster area of the 1995 Hyogoken-Nanbu Earthquake. Although the influence of the earthquake was much less compared with that on surface structures, in 20 to 30 mountain tunnels, some influence of the earthquake was observed, and around 10 tunnels among them had remarkable damage to need repair and reinforcement. A large part of the damage locations in the tunnels suffered coincided with the locations of existing faults and fracture zones which had been recognized during construction, as is the same characteristics as was known in the past experiences.