| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that a shield machine can not be modified repeatedly so as to have an expanded diameter or a contracted diameter and the diameter of a cutter disk cannot be easily changed and it is difficult to change the diameter of a tunnel while the mount conditions of a plurality of shield jacks are being maintained. SOLUTION: In a shield machine or 1B with its expanded diameter, there are provided, in addition to its internal devices, a first front drum 2, a second front drum 50, an inner bent part 4, the forward end 3a of a first rear drum, a ring web material 17, and a second rear drum 51. The drum 50 and drum 51 are fixed so as to be removed, and a second eccentric fitting 64 is connected to each shield jack 12 and the diameter of a cutter disk 5 also is expanded. For modifying the shield machine 1B to a shield machine or with a contracted diameter, the drum 50 and drum 51 are removed and the forward end part of the drum 2 is restored, and parts of the first rear drum, other than the forward end 3a, are restored, and a first eccentric fitting is connected in place of the fitting 64 to make the diameter of the cutter disk smaller. |
