PILE STRUCTURE AND CONSTRUCTION METHOD OF PILE

PROBLEM TO BE SOLVED: To provide a pile structure and a construction method of a pile, capable of suppressing a construction cost, environmental loads and extension of a construction period and then efficiently increasing axial force of a pile.SOLUTION: The pile structure includes a shaft part 12 whose flat sectional shape is rectangular and an enlarged bottom part 14 whose flat sectional shape is circular, for which the bottom part of the shaft part 12 is enlarged in a soil support layer, and the enlarged bottom part 14 is configured so as to be enlarged to the side over the entire periphery at the bottom part of the shaft part 12. A hole for forming the shaft part 12 is drilled by using a horizontal multi-axial type drilling machine, and thereafter, the bottom of the hole is enlarged using a reverse circulation method.