| 摘要 |
PROBLEM TO BE SOLVED: To provide a cutter bit exchanging method for a shield machine, which can safely and easily carry out exchange of cutter bits without requiring a large work space on the ground at a low cost and in a short period of time, irrespective of a tunnel bore. SOLUTION: The shield machine 1 has a cutter ring 10 having a cutting bit 11 at its front edge, and the cutter ring 10 is arranged on the periphery of a tunnel excavating cutter 4 in a manner being protrudable from a shield machine main body 1a in a frontward direction of the cutter 4. Tunnel excavation is carried out by using the shield machine 1 thus formed. Then, an impervious underground wall 20 is constructed by using a hardener such as concrete at a location to which the shield machine is expected to drive, and the excavation of the shield machine 1 is stopped immediately before the underground wall. Then, the cutter ring 10 is rotatively protruded, and the underground wall 20 is circularly cut by the tip of the cutter ring, followed by fitting the tip of the cutter ring 10 into the circular groove thus formed. Thereafter, earth and sand in the cutter ring 10 is discharged, and then exchange of the cutter bits 5 is carried out in a dry work space 22 defined by the tunnel excavating cutter 4 and the underground wall 20. |
