PROBLEM TO BE SOLVED: To restrain reduction in strength of a crushed stone pile.SOLUTION: A crushed stone pile formation device 100 comprises an attachment 10 for forming a crushed stone pile in a space while rising from underground by forming the space by being inserted into the ground, a driving device 11 for generating rotational driving force and a crushed stone holder 30 installed on the ground surface and having a through-hole capable of penetrating the attachment 10. The attachment 10 includes a cylindrical part 12 and a spiral part 14 rotatably arranged in the cylindrical part 12, connected to the driving device 11 and excavating underground. The crushed stone holder 30 is constituted so that a crushed stone can be thrown into the space in the through-hole enclosed by the tip of the attachment 10, the ground surface and the crushed stone holder 30 in a state before inserting the attachment 10 into the ground, and the attachment 10 is inserted into the ground in a state of penetrating through the through-hole of the crushed stone holder 30 in a state after inserting the attachment 10 into the ground.SELECTED DRAWING: Figure 1
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