ABSTRACT
The New Kobotoke Tunnel Project on the Chuo Expressway is a construction project to excavate a new tunnel as a separate line to the north area of existing inbound lane of the Kobutoke Tunnel, which is currently in service, to alleviate traffic jam. The new tunnel is planned to have five evacuation tunnels connecting to the existing inbound lane tunnel which was constructed by timbering support method. Since connecting the evacuation tunnel with the existing tunnel was expected to affect the lining of the existing tunnel, the impact was predicted in advance and the reinforcement and measurement of the existing lining were planned. The details of the plan will be presented in this paper.
