| 摘要 |
<p>PURPOSE:To replace an existing pipe easily with high efficiency. CONSTITUTION:After cutting an existing pipe 1 circumferentially at spaces in the pipe axis direction by a cutting device 2, the outer peripheral ground of the existing pipe 1 is excavated ahead by an advancing pipe 3 with its inner diameter larger than the joint outer diameter of the existing pipe 1, and the front part of a propulsion pipe 3 that can pass outside the existing pipe 1 is connected to the rear part of the advancing pipe 3. The cut existing pipe is then held by fitting/removing mechanism 5 in a removing device 6 so as to be moved into a start shaft 7. While repeating the circumferential cutting of the existing pipe 1 by the cutting device 2 and the movement-removal of the cut existing pipe by the removing device 6, the existing pipe 1 in a unit work block is replaced with the propulsion pipe 4 that is used as a new pipe.</p> |
