| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform continuous propulsion at a low cost without using an intermediate pushing device of a conventional ST pipe for any curvature radius in the case of performing a steep curve jacking method by an intermediate pushing method. <P>SOLUTION: A recess 24 is formed at the insertion port end part of a pipe whose length is the same as or shorter than a standard propulsion pipe to be used to attain a propulsion pipe 20 with the recess for jack attachment. Base pushing is performed by a base pushing device while adding a plurality of propulsion pipes first, the plurality of the propulsion pipes 20 with the recess for the jack attachment, for which a jack 30 is attached to the recess 24, are continuously added to the propulsion pipe column, and propulsion is performed to the middle by the base pushing device while adding the plurality of propulsion pipes further. Then, the base pushing device is stopped, the front jack 30 is extended, and the intermediate pushing of the propulsion pipe column on a face side is performed. Then, the rear jack 30 is extended, the front jack 30 is contracted, the following propulsion pipes 20 with the recess for the jack attachment are successively moved to the front one by one, and the propulsion pipe column on a start side is base-pushed by the base pushing device thereafter. <P>COPYRIGHT: (C)2012,JPO&INPIT |
