| 摘要 |
PURPOSE:To construct sand pillars having specified diameter and shape while avoiding the upward escape of water from the side of the sand pillar by a method in which a circular part is inserted into a casing and then sand is packed in the circular part. CONSTITUTION:A circular part 18 is inserted into a casing 4 and then sand is packed in the circular part, whereby the circular part 18 is lowered in the casing 4. When it reaches the surface of water W in the casing 4, a pressure originated from the weight of the sand pillar is applied to the water W and the water W is discharged through a drain pipe 17 from a drain port 16, combined with the action of a drain pump. After the sand pillar reaches the bottom, the casing 4 is pulled up, along with a bottom cover 20, and the sand pillar is left under the soft ground 1. Since a pressure originated from the weight of the sand pillar is applied on the water W in the casing 4 and the water is discharged through the drain port 16 to the surface, the sand pillar can be constructed in a specified dimension. |
