| 摘要 |
PROBLEM TO BE SOLVED: To prevent the contact of a skin plate and a ground in the case of following excavation and facilitate the direction change of an excavator by forming a triangular recess part in plan view on the skin plate rearward of the side cutter of the excavator. SOLUTION: A shield excavator 10 has a main cutter 1 in the center, sub- cutters 2, 2 on both the sides, and side cutters 3, 4 on the corner part, and excavation is performed adjacent to a tunnel excavated by a preceding excavator, which excavates part of a filler such as mortar formed for earth retaining and water sealing. In the shield excavator 10, recess parts 5, 6 in plan view are formed on the sideward part of skin plates 3A, 4A rearward of the side cutters 3, 4. Thereby the shield excavator 10 can easily turn without bringing the skin plates 3A, 4A into contact with the filler. Preceding excavation can be performed in the state of the absence of the recess parts 5, 6 by detachably mounting a cover member on the recess parts 5, 6. |
