| 摘要 |
<p>PURPOSE:To replace an already laid pipe to a newly constructed pipe from the ground surface by advancing a screw part having a cutting edge revolving rod into an already laid pipe and fitting a newly constructed pipe onto the periphery of the cutting edge revolving rod and breaking the already laid pipe by the cutting edge and advancing the newly constructed pipe at the same time. CONSTITUTION:The screw part 17a of an auger rod 17 is advanced into an already laid pipe 2 from a starting vertical hole 22, and when said screw part 17a reaches a prescribed position, a rod part 17b is connected. A cutting edge revolving rod 19 having a cutting edge 18 is fitted onto the outer periphery of the rod part 17b. A newly constructed pipe 3 is fitted onto the outer periphery of the cutting edge revolving rod 19 through a center holding tool 24, and the auger rod 17 and the cutting edge revolving rod 19 are revolved and advanced, and the already laid pipe 2 is broken by the cutting edge 18. At the same time, the newly constructed pipe 3 is advanced, and after the cutting edge 18 and the newly constructed pipe 3 reach a final vertical hole 23, the cutting edge 18, etc., are removed. Therefore, the gas pipes, etc., in the vicinity can be protected from being broken. Further, since the construction can be carried out through the dry method, the need of pumps, etc., is obviated, and the generation of muddy soil is prevented.</p> |
