Research on Energy Dissipation Pattern for the Surface Outlets of Sanhekou Hydropower Project

The Sanhekou Hydropower Project is designed as for the RCC arch dam.The main outlet structures are three overflow surface outlets and two bottom outlets,and all outlets adopts the ski-jump dissipation pattern.To mitigate the erosion of the dam toe and the river bed,a plunge pool is set up at the downstream of the dam.In the original design,the flow from the surface outlets is too highly centralized,causing bringing larger fluctuating pressure on the plunge pool,which is disadvantageous threatening to the safe operation of the plunge pool.Based on the model tests,in the latest selected dissipation scheme,the flow can be dispersed furthest,and the flow pattern and pressure distribution in the plunge pool is obviously significantly improved.