| 摘要 |
PURPOSE:To place gravels around piles regardless of the quality of the ground by a method in which a split cylinder which can be opened is driven into soft ground by an oil-pressure cylinder, gravels are supplied into the cylinder, and a knitted pile is driven into the cylinder in such a way that the cylinder is expanded or contracted when a knot is reached. CONSTITUTION:A hollow cylinder 1 is formed by connecting two or more split cylinders 1a and 1b by an oil-pressure cylinder 21. The cylinder 1 is driven through a cone into soft ground, gravels 7 are supplied into the cylinder 1, and a pile 9 with knots 8 is driven slowly into the cylinder 1. When the knot 8 is present in the lower part of the cylinder 1, the cylinder 1 is expanded or contracted at its lower part 3 by utilizing its upper end as a supporting point. The procedure is repeated to collect gravels around the pile. The pile can thus be quickly driven regardless of the quality of the ground. |
