The rectilinear propulsion which you can do with the one pushing driving force which accompanies the continual revolution where

摘要

PROBLEM TO BE SOLVED: To jack a pipe into a gravel layer and a rubbish or the like in the case of a collision against the gravel layer and a junk or the like including a construction waste material or the like, and to lay various kinds of pipes in the ground regarding a one-way pipe jacking method of a non-open cut type.;SOLUTION: An inner bit 10 is installed at a front end in the pipe-jacking direction of an inner tool, and an outer bit 1 is mounted at the front end section in the pipe-jacking direction of an outer tool in which the inner tool is interpolated. A percussion transmission section 19 is formed to the inner bit 10, percussion excavation by both bits 1 and 10 is enabled by a collision against the inclined stepped section 13 of the outer bit 1 of the transmission section 19 and the gravel layer and the junk can be jacked with a pipe even in the case of the collision against the gravel layer and the junk or the like including the construction waste material or the like.;COPYRIGHT: (C)2004,JPO&NCIPI