ABSTRACT
The Abo Tunnel is located on the Chubu Jukan Expressway between Matsumoto City in Nagano Prefecture and Takayama City in Gifu Prefecture. Completed in 1997, the tunnel stretches 4,370 meters and was built by overcoming difficult conditions such as high-temperature zones, weak ground areas, and high-water pressure zones due to its passage through the Norikura volcanic zone. Since its opening, various deformations have occurred, and countermeasures have been taken accordingly. Now, 26 years after its construction, a maintenance management manual has been developed, which organizes the risks of deformations and outlines the corresponding action plans to ensure proper maintenance. This report introduces the countermeasures for deformations taken in the Abo Tunnel so far and summarizes the maintenance management approach for the Abo Tunnel’s escape tunnel.
