CUTTING EDGE STRUCTURE OF UNDERGROUND STRUCTURE

PROBLEM TO BE SOLVED: To provide a cutting edge structure of an underground structure for stabilizing a working face by preventing falling-in of the natural ground from a cutting edge upper part when jacking the underground structure for arranging a cutting edge on the tip. SOLUTION: In this cutting edge structure of the upper part of the underground structure buried in the ground by jacking, and being a box body having the cutting edge in the upper part and both side parts; a cylinder 13a of a slide jack 13 is fixed to a front end part of the box body; a rod 13b of the slide jack 13 is installed in a receiving cylinder fixed to a lower part of the cutting edge 9a of the upper part; the cutting edge 9a of the upper part is forwardly advancingly arranged independently of the box body; an installing part of the rod 13b to the receiving cylinder 14 penetrates through the rod 13b so that pin round steel 15 fixed to the receiving cylinder 14 is orthogonal to the rod 13b; and the cutting edge 9a of the upper part is combined with the rod 13b so as to freely rise up and fall down. COPYRIGHT: (C)2005,JPO&NCIPI