2004 Volume 14 Pages 71-82
During the construction of Inasa No.2 Tunnel on the New Tomei Expressway, both portals, northern starting point and southern ending point, have been subject to large-scale landslides. Based on the obtained knowledge through the construction at the north portal, this paper describes the landslide mechanism caused by tunnel excavation nearby, and the effect of countermeasure against landslide actually implemented in the construction of tunnel.