| 摘要 |
<p>PROBLEM TO BE SOLVED: To pull in a steel pipe over a long distance which is conventionally impossible by a propelling machine alone by effectively utilizing a road setting type propelling machine. SOLUTION: A starting bored hole 1 is provided in one side of a pipe laying path, a destination bored hole 2 is provided in the other side, a road setting type propelling machine 3 having a guide drill unit 31 is installed on the round of the starting bored hole side 1 and a returning device 5 having a propelling jack is installed in the destination bored hole 2. In first step, a drill head is attached to the tip of a rotary rod 4 delivered from the road setting type propelling machine 3, advanced into the ground while rotating the drill head and boring hole is drilled up to the destination bored hole. In second step, the drill head is removed in the destination bored hole 2, instead by serially connecting an expanded hole rimer 6 coincided with a buried pipe diameter and a steel pipe 7 to be pulled in to the end part of the rod 4, the rod 4 is returned by a pulling-in force from the front by the propelling machine 3, and by simultaneously adding a pushing-in force from the rear side by the returning device 5 to the rear end part of the steel pipe 7 to be pulled in, the steel pipe is pulled in.</p> |
