| 摘要 |
PURPOSE:To prevent the water leakage through the bottom of a sand-bag pillar by uniformly packing sand in the longitudinal direction of the sand-bag pillar by providing an auxiliary material for forming the sand-bag pillar at the bottom and its neighborhood thereof in the manufacture of the sand-bag pillar. CONSTITUTION:An auxiliary material 18 for forming a sand-bag pillar is inserted into the sand-bag 9 whose bottom is formed into an almost circular shape, and then sand is packed into the sand-bag 9. The auxiliary material 18 used is a doughnut-shaped or disc-shaped part with plural holes. The sand-bag 9 with the auxiliary material 18 is placed on the surface of water W filled to part or mouth of the casing 4, and by utilizing the bottom of the sand-bag pillar as a piston, sand is packed into the sand-bag 9. In this case, by reducing tensile stress applying to the sand-bag 9 or controlling the drain of water W in the casing 4, the sand-bag can be slowly brought down in the casing 4. |
