DISCHARGING METHOD OF SEDIMENT IN DAM STORAGE RESERVOIR

PROBLEM TO BE SOLVED: To provide a method, in which a sediment can be discharged surely at any time regardless of the pondage, water usage, etc., of a dam storage reservoir. SOLUTION: Soil-sand intakes 26 in a cylindrical body are opened, an air supply pipe 18 is closed by an on-off valve 36 and a weight 16 is moved from the lower section of the cylindrical body to an upper section, and a sediment 24 is flowed out into the cylindrical body from the soil-sand intakes 26. The soil-sand intakes 26 are closed under the state, in which the weight 16 is placed at the upper end of the cylindrical body, the weight 16 is lowered by its own weight, and sediment 24 is shifted to a soil-sand discharging pipe 14 from a communicating port 28. The communicating port 28 is closed by the weight 16, the on-off valve 36 is opened, a spherical body 20 is charged to the air supply pipe 18, the spherical body 20 is moved to the lower section of the air supply pipe 18 by compressured air, and inserted into the sediment 24 in the soil-sand discharging pipe 14, and the spherical body 20 and the sediment 24 are shifted and discharged on the storage reservoir 6 side by the further supply of compressed air.