Experimental Study of Discharge Doefficient of the Groove upstream of Concrete-Face Rockfill Dam (using Hydraulic Models)

Considering the role of heterogeneous dams in flood control and also water storage, its very important to consider the flow hydraulic in them. On the other hand, proper design of Rockfill dams requires accurate study of flow behavior in these dams. In this regard by studying the concrete-face rockfill dam (CFRD) in the present study, by creating different cracks on the concrete face of the dam in the laboratory model, the water infiltration behavior inside the dam body was investigated. Transverse cracks of concrete slab on CFRD Dam and water flow and how to control it in CFRDs is one of the most important issues considered by experts in the design of dams. Determining the discharge coefficient of the groove to estimate the flow rate is important and unavoidable. The purpose of this study is to calculate the discharge coefficient of a rectangular groove located in the concrete surface upstream of the CFRD in both submerged and free conditions. Variable geometric parameters in this study include the height of the groove from the bed, the angle of the groove located upstream of the horizon and the variable hydraulic parameters include the height of the water head upstream of the CFRD. two equations were developed using dimensional analysis and nonlinear equation analysis, in order to predict the CD of the upstream groove of a CFRD dam in both free and submerged states. The equations are in good agreement (correlation coefficient of 0.988 (free ) and 0.984 (submerged )) with experimental results.