PROBLEM TO BE SOLVED: To improve strength and deformation performance of a pile head joining part equal to a level equal to or higher than a conventional system.
SOLUTION: This structure joins a cast-in-place RC pile 1 and a footing 2. An outer diameter of a first joining part 11 being a part of the cast-in-place RC pile 1 joined to the footing 2 is set to D1 equal to an outer diameter of a first general part 12 being the other part, and is set at a substantially right angle in the first main reinforcement direction by surrounding the periphery of a plurality of first main reinforcements 25 in the first joining part 11. A reinforcement quantity is set larger than a quantity of first general part hoop tie 27 of the cast-in-place RC pile 1. A dense reinforcement section hoop tie 28 is arranged, and a synthetic resin sheet 31 is adhered so as to surround the first main reinforcements 25 in the vicinity of a first boundary part 13. Thus, strength and deformation performance of reinforced concrete in the vicinity of the first joining part 11 can be increased, and rupture of the first main reinforcements 25 can be prevented in an earthquake.