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: A drill pipe 10 is supported by a working machine 12 arranged onto a bank body 4 or supported by a pontoon 14 floated on the dam storage reservoir 2. The sediment 34 is discharged in such a manner that the drill pipe 10 is lowered while being rotated, a drill section is pressed into the sediment 34, and compressed air is discharged from compressed-air blow-off ports. Consequently, the sediment 34 is intruded into the drill section from the soil-sand intake. The sediment 34 is transferred upwards in a steel pipe by an air lift effect by upward movement in the steel pipe of compressed air discharged from the compressed-air blow-off port, and transported and discharged into a grit chamber 8 or a sediment recovery ship 36 through a sediment discharge pipe 30.