| 摘要 |
PROBLEM TO BE SOLVED: To provide a connection structure of backfilling agent supply pipes, capable of reducing a ground-change state after extracting an existing pile and backfilling, and capable of shortening a construction period.SOLUTION: The problem is solved by a connection structure of backfilling agent supply pipes as follows. The connection structure includes: first and second backfilling agent supply pipes 81 and 82 each formed with a connection part 80 having a semi-cylindrical part 83 and an inscribed cylindrical pipe projection part 86; and an engaging holding pipe 90 for restricting an engaging state in such a manner that both the connection parts 80 are made to face each other while deviating axes of the connection parts 80 from each other parallel, and one of both the semi-cylindrical parts 83 is fitted with the another side inscribed cylindrical pipe projection part 86 coaxially, then the engaging holding pipe 90 is externally fitted on outer peripheries of both the connection parts 80. There is provided a lock projection part 88 projecting from a part of an outer peripheral part of the first backfilling agent supply pipe connection part 81. There is also provided an introduction part 93 being a groove opened in the engaging holding pipe 90 and enabling going-in and going-out of the lock projection part 88 at one end of the pipe 90, and having a circumferential groove 94 extending in a circumferential direction of the engaging holding pipe 90 and a rotation preventive groove 96 extending in the axial direction. |
