Opening poly number of starts pipe conduit collective pulling included construction methods and its device

摘要

PROBLEM TO BE SOLVED: To provide a method for batch-drawing multi-line conduits, which allows curved drawing or curved laying of the conduits even if each pipe has a considerable length of 4 m or so without plasticity. ;SOLUTION: According to the method, a wire is stretched under the ground from a starting shaft to an arrival shaft, and an underground hole diameter expanding device is attached to an end of the wire, followed by connecting a drawing wire 11 to the rear of the device. Then, the pipes 17 without plasticity are bound together as a unit, and a joint portion 17a of each pipe 17 is engaged with a pipe bearer 12 which is then inserted into the multiple pipes 17 and borne by the same, followed by inserting the drawing wire 11 into an almost central location of the pipe bearer 12. To connect the unit pipes 17 together, one end of one of the pipes 17 is slidably inserted into the joint portion 17a of the pipe 17 adjacent thereto, and while the one end of the adjacent pipe 17 is axially spaced a predetermined distance away from a deep end of the joint portion 17a of the one pipe 17, the pipe bearer 12 is fixed to the drawing wire 11. Further, a tapering cap is attached to an opening of each pipe 17 of the leading unit, for blocking the same, and then the wire is towed.;COPYRIGHT: (C)2003,JPO