| 摘要 |
PURPOSE:To allow a spreader at the top end to make contact with the end surface of a segment almost at right angle, even if a rod is extended, after the contraction of a shield jack, in the excavation work of a curved-shaped tunnel. CONSTITUTION:Each body top end part of a plurality of shield jacks 5 arranged, keeping an interval in the circumferential direction along the inner peripheral surface of a rear trunk 3 is supported in a swingable manner through a spherical bearing on the rear trunk 3. The part close to the body basic part of the shield jack 5 is grasped by a swing plate supported in a swingable manner at least in the horizontal direction for the inner peripheral surface front end part of the rear trunk 3, and one end of the swing jack 12 is pivotally installed at the inner peripheral surface front end part of the rear trunk 3, and the other end of the swing jack 12 is connected with the swing plate. |
