18-12, Nishiochiai 2-chome,
Shinjuku-ku, Tokyo 161-8575, Japan
Phone: +81-3-5906-0211
FAX: +81-3-5906-0112

Water Resource Development

BACKGROUND & PURPOSE OF PROJECT

For this project, we identified the type of selective water-intake installation to be used in the Shitsumi Dam, and then defined its execution design.

CHARACTERISTICS, CONCEPT, STANCE & SKILLS OF PROJECT

For this project, we adopted a "continuous siphon type water-intake installation", which is a new type of selective water-intake installation that uses air to stop water. This installation can intake water through the selected water-intake pipe without the use of a steel gate or a separate switchgear.

We adopted the use of a continuous siphon type water-intake installation to operate as a selective water-intake installation and optimized the design of the intake pipe to comply with design conditions such as the water-intake amount. We also designed the swash gate, maintenance gate, water filling device, and air pipe of the permanent spillway.

EFFECT OF PROJECT

Costs were reduced by approx. 20% through the adoption of the continuous siphon type water-intake installation compared to conventional design plans. This also saved on labor with regards to maintenance. In addition to this, the protruding structure on the dam crest was eliminated by locating the water-intake installation control room within the dam body, simplifying the appearance of the dam.