| 摘要 |
<p>PROBLEM TO BE SOLVED: To accurately correspond to the circumstantial variation of the wall of an excavated hole for smoothly arranging a pipe on a laying track in the case of laying the pipe under the ground. SOLUTION: In a method for laying a pipe in arc-shape under the ground by balancing buoyancy produced by muddy water 10 acting on an external pipe 2 with the weight of a pipe 1 and filled up water 13a, 13b, water 13a, 13b is discharged from or filled up in one or both of a gap between the external pipe 2 and an inner pipe 3 or the inner pipe 3. Thus a balanced state among the buoyancy produced by the muddy water 10, the pipe 1 and water 13a, 13b is broken to make the pipe 1 float or sink in the longitudinal direction of the pipe 1 for pressing the wall of an excavated hole 8 to enlarge it, and frictional force between the hole wall and the external pipe 2 can be thereby reduced to smoothly arrange the pipe 1 on a laying track.</p> |
