ABSTRACT
The Hakkoda Tunnel in the section between Ha-chinohe and Shin-Aomori of the Tohoku Shinkansen Line-1 is a long mountain tunnel of a length of 26,455 m, the longest on land in the world when it is completed. Excavation was started from both portals in the village of Temmabayashi and in the city of Aomori. This paper describes how the unconsolidated water-bearing stratum was excavated in the Nashinoki plateau consisting of pyroclastic deposits from the Volcano Hakkoda on the Aomori side (in the Nashinoki Section of the Hakkoda Tunnel of the Tohoku Shinkansen line). Deep wells of a height of 150m were used for lowering the ground-water level.
