Abstract: An experimental study was conducted to investigate the scour prevention of downstream slopes in steep narrow valleys based on the ski-jump energy dissipation of the overflow tunnel at Lawa Hydropower station. The hydraulic characteristics of the slopes were analyzed using both fixed bed and moving bed tests. The experimental findings indicate that the water flow pattern, near-bank velocity, and fluctuating pressure of the skew bucket are superior to those of beveled flip bucket. Additionally, the elevation of the maximum impact pressure point on the riverbank is close to the lowest elevation of bedrock’s capacity to withstand scouring velocity. The scour pattern on steep slopes simulated with granular soils aligns well with the flow velocity law observed in fixed bed banks, thereby providing a more accurate representation of the damage caused by water scour on steep bedrock slopes. These research results hold significant reference value for determining bank slope support, protection depth, and support structure design in similar projects.

Key words: ski-jump energy dissipation, skew bucket, beveled flip bucket, slope erosion prevention, fluctuating pressure, scouring experiment