| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a branch port opening construction method that can reduce cost without causing the increase of work manhours and work hours. SOLUTION: In a branch port opening construction method for opening a branch port in a main branch pipe buried under a road, without open-cutting, a communicating hole 6 is cut open from an optional position on the ground to a branch port opening part of the main branch pipe, and a water jet nozzle 10 for jetting high pressure water is led into the communicating hole 6 from the ground. The water jet nozzle 10 is moved close to the branch port opening of the main branch pipe, and the branch port is opened in the main branch pipe with high pressure water jetted from the water jet nozzle.</p> |
