FOOT PROTECTION METHOD FOR ROTARY PENETRATION PILE

PROBLEM TO BE SOLVED: To provide a foot protection method for a rotary penetration pile, capable of forming a foot protection of uniform quality by sufficiently stirring and mixing excavated sediment and a hardening fluid together.SOLUTION: A foot protection method for a rotary penetration pile is used to form a foot protection by using a rotary penetration pile 10 comprising a pile body 11 made of a steel pipe with a tip blocked by a bottom cover 12, a spiral blade 13 provided on an outer peripheral surface near the tip of the pile body 11, and an exhaust nozzle 14 for a hardening fluid provided on the outer peripheral surface. An injection piping 15 for injecting the hardening fluid is arranged in the pile body during construction; one end of the injection piping is connected to the exhaust nozzle; the pile body is rotatingly penetrated into a ground; the hardening fluid is injected from the injection piping into a bearing layer via the exhaust nozzle by vertical movement of the plurality of times of the tip part of the pile body within a foot protection construction section Aa of the bearing layer of the ground while rotating the pile body; sediment in the bearing layer and the hardening fluid are stirred and mixed together by the spiral blade, and the foot protection is formed around the tip part of the pile body in the bearing layer.