PROBLEM TO BE SOLVED: To facilitate secure and appropriate retention of a wire rope at the lower end of a casing screw without the need for skill by improving a small-scale pull-out construction method for a subterranean residual pile and realize secure release of retention and secure fastening of a pile by the ring of the wire rope.
SOLUTION: In the pull-out construction method for the subterranean residual pile, the ring part 15 of the wire rope 6 is retained at the lower end of the casing screw 5, and a means of releasing the retention is provided. The casing screw is lowered in a sate where it is brought into engagement with a subterranean residual pile 14. After releasing the retention of the ring part by the releasing means, the casing screw is removed by leaving the ring, and the pile is pulled out by pulling the wire rope. The retention means inserts a thread body 9 into a plurality of small holes 10 formed in the vicinity of the lower end of the casing screw and retains the ring, and the releasing means places the midpoint of a rope 19 for release along the ring of the wire rope and ties the midpoint of the rope 19 for release and the ring of the wire rope together with the thread body 9. Then the thread body 9 is cut by pulling the end on the ground side. The wire rope is wound twice in the ring part. The jig 1 has a table, an inner support 3, and a guide 11. The inner support part 3 supports the part of the ring part, and the guide part 11 is provided by corresponding to the clearance 8 between the inner support parts 3. The thread part, which is inserted into the small hole of the casing screw, is guided by the guide part 11 so that it can go around the part of the ring and turn up.
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