Japan Society of Civil Engineers Annual Meeting

Due to climate change and flood intensification, there is an urgent need for dam upgrading project to increase discharge capacity in Japan. The purpose of this research is to improve dam function by arranging a siphon spillway on the dam body. The researchers developed a new technology for siphon spillway that maintains siphon function by installing a gate at the outlet. Hydraulic model test was conducted to study the feasibility of outlet-controlled siphon. As a result, it was concluded that excessive negative pressure and air entrainment can be avoided by adjusting the discharge gate, and siphon spillway is applicable as a temporary facility such as a water level lowering facility.