NEW-OLD GAS FEED PIPE REPLACING LAYING METHOD WITHOUT OPEN-CUTTING AND DEVICE THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a construction method and a device that can lead in new and old pipes for laying by manual work without open-cutting. ;SOLUTION: Soil at both ends of a replacing laying area is excavated until an existing gas feed pipe 3 is exposed to provide traction side and drawing side vertical holes 1, 2. A traction device 4 using a chain block 9 is set in the traction side vertical hole 1. A chain 11 of the traction device 4 and the existing gas feed pipe 3 are connected using a holding metal fitting 13. The tip of a synthetics resin pipe 35 is led into the drawing side vertical hole 2, and the synthetic resin pipe 35 and the existing gas feed pipe 3 are connected using a universal joint 28 and a connecting adaptor 21. The chain block 9 is then driven in the traction side vertical hole 1 to tow the existing gas feed pipe 3 and hereby to draw in the synthetic resin pipe 35. The existing gas feed pipe 3 exposed being towed to the length allowed in the traction side vertical hole 1 is cut at the root. The holding metal fitting 13 is set again to the cut part, and the chain block 9 is driven to draw in the synthetic resin pipe 35 while towing out the existing gas feed pipe 3. This process is repeated to replace the existing gas feed pipe 3 with the synthetic resin pipe 35.;COPYRIGHT: (C)1998,JPO