ABSTRACT
The Tsuruga Maintenance and Service Center of the Central Nippon Expressway Company Limited constructed an evacuation tunnel to connect the upper and lower lines of the Habara Tunnel on the Hokuriku Expressway for increased safety. As the construction started, monitoring measurements of the service tunnel increased. Saddles were used to provide emergency reinforcement, and additional reinforcement work was carried out in the main shaft and the evacuation tunnel. The additional reinforcement work was carried out using 3D FEM analysis to capture changes in stress from the time the tunnel main shaft was constructed, and construction was carried out in a manner that did not affect the service tunnel. These measures helped the evacuation tunnel to be finished. The following is a report on some points we found when connecting the evacuation tunnel to the service tunnel.
