PURPOSE: To increase the bearing force of piles by a method in which a multidirectionally expandible anchor is set on the bottom of a pit, a necessary number of iron bars are set on the anchor, an iron bar net is inserted into the pit, and concrete is packed into the pit and hardened to form a pile.
CONSTITUTION: An upper cover plate 6 is fitted on the first and second resistance plates 1 and 1' combined with a rotary shaft 7 on the first base plate 5, and a rotary angular shaft 8 is fitted into and fixed to the shaft 7 to form a two-way expandible anchor. Iron bars 17 are connected with the shaft 8 of the anchor and a receiving shaft 9 and set on the bottom of a pit. A rotary angular pipe 18 is fitted into the shaft 8 under the quidance of the iron bars 17, and the plates 1 and 1' are completely expanded by operating the pipe 18. The iron bar net (not illustrated) is inserted into the pit in such a way as to build all the iron bars 17 inside, and then concrete is placed into the net and packed from the notched portion N of the plate 6 into all spaces on the plate 5 to construct a reinforced concrete pile (not illustrated) with two-way resistance plates 1 and 1'.
WATANABE HIKOITSU
GENMA SANJI