| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that, when constructing a tunnel, although an excavation portion is crushed using much energy and crushed pieces are discarded, it is desired that energy consumption is saved and the excavation portion is not discarded but is effectively utilized. <P>SOLUTION: A tunnel is constructed by excavating on the excavation outer edge line of the tunnel toward the depth, creating a tubular rock piece and destroying its deep end to draw it out. As a method for excavating the excavation outer edge line of the tunnel toward the depth, boring is performed in the excavation outer edge line toward the depth at appropriate intervals, and a clearance of holes is cut by a stone saw around the hole. In order to smoothly draw the tubular rock piece, first of all, a tubular rock piece with a narrow upper portion and a wide lower portion is created, the deep end is destroyed and the tubular rock piece is dropped down, thereby creating the clearance between bedrock and the rock piece. <P>COPYRIGHT: (C)2013,JPO&INPIT |
