Step type overflow dam

A transition step and an energy dissipation step are arranged on the downstream of the overflow dam, the outer wrapping line of the energy dissipation step is tangent to the downstream weir surface curve of the overflow dam, and the transition step is located above the tangent point of the outer wrapping line of the energy dissipation step and the downstream weir surface curve. The outer envelope line of the transition step coincides with the downstream weir surface curve of the overflow dam, and the inner envelope line of the transition step is the extension line of the midpoint connecting line of the horizontal section and the vertical section of the energy dissipation step. The structure is simple, construction is convenient, the transition step is arranged between the tail end of the weir surface curve and the conventional step, the flow state of initial discharged water flow is stable, no hydraulic jump is generated on the horizontal section of the step, water splashing is prevented, and damage of high-s