| Ground water drainage method has been carried out for lowering ground water level and stabilizing the slope.On its constructing procedure, drainage drill hole is usually covered with a casing pipe that is conventionally made of either steel or PVC and is perforated with small holes on it. These conventional casing pipes are pointed out for losing the drain potential due to clogged hole on pipe surface and/or soil draw-out from the holes. These days, several new type casing pipes, each of which has features to enhance drain efficiency, are developed and applied for in-situ site. The authors, then, carried out drainage efficiency test with earth tank, which is assumed unstable ground like as surface sediment, and compare these pipes’s drainage performance. |
