| 摘要 |
<p>PROBLEM TO BE SOLVED: To establish a pipe laying method for an underground embedded pipe using the propulsive working method, with which there is no risk that the pipe is tightened by the ground at the time of drawing in and becomes incapable of being drawn in. SOLUTION: An iron pipe 2 furnished with a notch 5 to allow easy rupturing and stretching in the axial direction is propelled under the ground. A diameter expansion tool 4 whose front extremity is smaller than the inside diameter of the iron pipe and tail is greater than the outside diameter of the iron pipe is connected with the tip of a wire 3 threaded through the iron pipe 2, and the tip of the embedded pipe 1 is connected with the tail of the expansion tool 4. The embedded pipe 1 is laid in the iron pipe 2 buy pulling back the wire 3 while the notch 5 is cut open by a cutter blade 6. The cut iron pipe 2 is left underground to serve as a support for preventing the embedded pipe 1 from being tightened by the ground and ensures the drawing-in of the embedded pipe 1. Because this method uses low-cots iron pipe 2, does not require muddy water spouting at the time of drawing in, and does not involve collection of a propelling rod, so that it is possible to reduce the material costs, man-hours for works, and the construction period to a great extent.</p> |
