| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily reduce the pipe insertion resistance making use of the buoyancy, and to reduce the cost in a horizontal pipe of relatively long span on land. SOLUTION: In either of a method where a seal mechanism 3 in which a pipe body 2 is slidable is provided on a starting side pipe end of an existing external pipe 1 in which the pipe body 2 is inserted, or a method where a liquid tank capable of being pumped is installed in a starting shaft 5, and the openable/closable seal mechanism 3 is provided on the straight side pipe end of the existing external pipe 1 is provided, the process where hollow pipe bodies are joined with each other in air in the starting shaft 5, and the pipe body 2 is pulled in or pressed into the existing external pipe 1 in which the buoyancy regulating liquid 4 is poured so that the weight of the pipe body in the liquid is approximately zero, is repeated to insert the pipes.</p> |
