Evaluation of selected equations for predicting scour at downstream of ski-jump spillway using laboratory and field data

The provision of spillways in the structure of a dam enables proper disposal of flood water in excess of the reservoir capacity, and regulates the energy of flowing water downstream. Some spillways dissipate energy in the form of ski-jump which leads to scouring process. Scour holes formed downstream of spillways may affect the safety and stability of the structure. Therefore accurate prediction of the scour depth is necessary to ensure the safety of dam as well as its abutments. The prediction procedure is extremely complex due to various hydraulic and geological factors influencing scouring phenomenon. Several researchers have developed empirical equations for scour depth predictions, keeping in view the above mentioned factors. It is noted from the literature that there are not many studies to evaluate the efficiency of these equations for scour depth prediction. Therefore, the present study attempts to evaluate different empirical equations available in the literature for scour depth prediction using experimental and field data reported in the literature. For this purpose, a database has been formulated based on the scour depth values reported in the literature.