| 摘要 |
PURPOSE:To prevent the blocking of draining materials by a method in which a mandrel housed with a draining material is penetrated into soft ground and only the mandrel is pulled up while discharging a flocculant from an outlet port at the tip in such a way as to flocculate the soil particles of the surroundings. CONSTITUTION:A vertical draining material B is inserted into a mandrel A having a water-passing tube 2 with an outlet port 1 at its lower end in the longitudinal direction, and its lower end is held by the holder 6 of the shoe C of the mandrel A. The mandrel A is penetrated to a given depth into soft ground by a vibro-hammer, etc., and then while discharging a 5-5,000ppm aqueous solution of a polyacrylamide high-molecular compound from the outlet port 1, the mandrel A is pulled up. Silt and clay in and around the drain material B left behind with the shoe C are mixed with the aqueous solution to flocculate (agglomerate) the soil particles. Accordingly, a thick filter layer is formed around the drain material B to prevent the clogging of the draining material B. |
