| 摘要 |
PROBLEM TO BE SOLVED: To provide a hollow pipe for creating sand piles capable of suppressing vibration and noise to a minimum, of omitting an electric motor or a swivel device and of restricting a rise in facility costs, and a circular sand pile creating method. SOLUTION: This method uses a cylindrical hollow pipe 1 into which a sand pile material is placed and a hollow pipe 4 for creating sand pile having protruded portions 2a to 2d each tip having an equal distance R from the center of the cylindrical hollow pipe 1, the section shape of each protruded portion has an almost triangle shape, and this pipe creates a sand pile of a circular cross section underground by reciprocating rotating operations.
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