To eliminate the necessity of a large scale facility and to reduce energy required for freezing a natural ground, during joining of two shield machines with each other underground.
In shield tunneling method in which shield machines are joined each other underground, a jet port 13a for freeze gas is formed in a food part 1a of a skin plate in the vicinity of the front end part thereof, and the freeze gas is jetted from the jet port 13 so as to freeze a natural ground therearound. Further, the shield machine has such an arrangement that the jet port 13a for freeze gas is formed in the food part 1a of the skin plate in the vicinity of the front end part thereof, and the freeze gas is jetted from the jet port 13 so as to freeze a natural ground therearound.
HIRACHI MASANORI
HAGIWARA TAKASHI
SAKAE TAKESHI
