HYDRAULIC CHARACTERISTICS OF FLOW AND ENERGY DISSIPATION OVER STEPPED SPILLWAY

N this research, water surface profile, piezometric head distribution and energy dissipation ( ? E/E 0 )%, were studied over a stepped spillway of semicircular crest.Different types of stepped spillway were used. Three types of d/s slope of the spillway ( α =V: H=1:0.75, 1:1 and 1:125) were used and three number of steppes (N s = 3, 5 and 7) for every slope. Seventy two experiments were performed in a laboratory horizontal channel of 12 m length, 0.5 m width and 0.45 m depth for a wide range of discharge.