| 摘要 |
PURPOSE:To prevent the generation of dust by excavating a bedrock to be broken at a fixed distance, moving a sliding plate installed on a frame and abutting the sliding plate against a face and covering the bedrock under an exposed state with the plate to tunnel space. CONSTITUTION:A bedrock is excavated only by a fixed distance L2, and a frame 15a is held so as to be formed to a similar shape to a tunnel cross section. A sliding plate 15c is projected to the face 16 side, a filling chock 19 is adapted to irregularities 1c, and a bedrock 2 section at the distance L2 is covered with the plate 15c to tunnel space 1a. Concrete mixed with an accelerating agent is is injected and placed into concrete placing space 20 shaped among a face 1b, the bedrock 2, the plate 15c and a lining 17. |
