The investigation of energy dissipation in ogee profile spillway model

Major failures of spillway occur due to the inadequate or inefficient design of the spillway. In the Khadakwasla dam spillway, Pune (Maharashtra) has erosion and scouring on the spillway bed. The roller bucket is the alternative to reduce the kinetic energy and minimize the length of the hydraulic jump. Hence, there is an urgent need to develop appropriate energy dissipators to intend for high discharges. To address these concerns, the current study concentrates on resolving them by implementing plain and slotted roller buckets for the ogee profile stepped spillway. The proposed approach involves combining roller buckets and stilling basins, integrating appropriate steps designed for the ogee profile stepped spillway. This is achieved through the creation of a physical hydraulic model in the laboratory, with a scale ratio of 1:33. A comprehensive model study was conducted and the performance was validated using the Froude model law and continuity equation for a design discharge rate of 900 m3/s. Performance evaluation of plain and slotted roller bucket for ogee and stepped spillway illustrated that 82% of specific energy is eliminated by a plain roller bucket and 78% by a slotted roller bucket. In a stepped spillway, 58% of specific energy is eliminated by a plain roller bucket and 57% by the slotted bucket. Hence, in this device, the ogee spillway with a plain bucket is more reliable than the stepped spillway and helpful in reducing the intensity of specific energy over the chute surface of the spillway at a low head of 4 m.