PURPOSE: To more densely compact sand by a method in which sand is pressed into a fixed tube by compressed air while the sand is vibrated by a vibrator provided at the lower part of a casing.

CONSTITUTION: A rotary driver 9 is turned, and a casing 6 is penetrated into the ground while being turned. When a given depth is reached, sand is charged into a fixed tube 11 from a hopper 5. After the charging of sand, compressed air is supplied into the fixed tube 11 from an air nozzle 13, a valve mechanism 12 is closed, as shown by full line, by the compressed air, and the pressure of air in the fixed tube 11 is raised. A vibrator 16 is actuated to apply vibration to the surrounding sand. The sand is pressed from above in the fixed tube 11 by the compressed air, compacted by the vibration of the vibrator 16, the casing 6 is pulled up, and the bottom cover 8 is opened. The sand is pushed out from the lower end of the fixed tube 11 to form a sand pile.