| 摘要 |
<p>PURPOSE:To replace an existing pipe with a new without excavation by giving a cutting line to a joint, rupturing the joint with a projection on an excavation leading pipe, and taking in splinters of the joint into the trunk part of the severed existing pipe using a scraper. CONSTITUTION:At a certain spacing in the pipe circumferential direction, a plurality of cutting lines extending in the pipe axial direction are given to the joint 2 of an existing pipe 1 using a vertical cutter 15 and a horizontal cutter 14 of a joint cutting device 10, which is movable and is inserted in the existing pipe 1, while cutting lines in the pipe circumferential direction are given to both sides in axial direction of the joint 2 using a circumferential cutter 13 belonging to the same cutting device 10. Then an existing pipe carryout machine 30 is inserted in the pipe 1, and an excavation leading pipe 20 having projections in specified position on the inner surface is put on the pipe 1, and excavation is performed forward while the projections are pressed to the outer surface of the joint 2. The severed existing pipe 1A is removed by the carryout machine 30 through a new laid pipe 5 which is coupled with the tail of the excavation leading pipe 20, and another new laid pipe is coupled with the tail of the first-named new laid pipe 5. These procedures are repeated, and thus replacement of the existing pipe 1 with new pipes 5 is achieved.</p> |
