| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a smooth long distance excavation at the time of work such as the extraction removal and propulsion of an established pipe by removing the earth and sand around an underground pipe and dissolving the restraint of the ground. SOLUTION: When an excavation pipe 1 can not be advanced by the restraint of an outer peripheral ground 2 during the removal work or propulsion work of an underground established pipe 1, a cylindrical jig 10 arranged a nozzle in its front/rear side is externally fitted on the outer periphery of the established pipe 1 or the excavation pipe 1 and a pressurized water 5 is supplied to this jig through a moving pipe 16 and jetted from the nozzle. By this injection, the earth and sand staying around the estabilished pipe 1 or the excavation pipe 1 is removed and peripheral surface friction is reduced. Thereby, the extraction removal of the established pipe 1 or the re-advance of the excavation pipe 1 is carried out.</p> |
