Determination of discharge coefficient of inbuilt spillway in rock- fill dams

According to the former researcher’s presented relations for flow through rock-fill porous media, the effects of physical characteristics was not studied separately. Hence, due to the application of these relations, physical characteristics of porous materials effect must be investigated separately. In various constructed physical models of porous media, the effect of several variables such as unified coefficient of materials, kind of materials, material gradation and material figures on the parameters such as void ratio, raggedness and specified surface area of materials have been studied. These parameters have a significant effect on the flow discharge coefficient through rock-fill porous materials. In the defined research during this paper, using artificial unique spherical materials with diameters of 10, 37 and 75 mm with the same configuration, the effect of parameters including specified area of rock-fill materials, figure of rock-fill materials and the size of rock-fill materials on the hydraulic characteristics of discharge flow through rock-fill porous media in rock-fill dam models with inbuilt spillway and spillways on the upstream face, have been studied. Also, using the data of these experiments in combination with the data of experiments of the former researches on the natural rock-fill materials, dimensionless relations of Bazargan have been investigated. Finally, using statistical multi variable analysis, a dimensionless relation with maximum correlation coefficient and acceptable accuracy based on the physical characteristics has been presented.