Scour control downstream of block ramps in basins with continuous and dentated sill

Hydraulic structures are often used for river rehabilitation. One of the main problem to consider for their design is the downstream scour control. Many studies are present in literature for the prediction of the scour hole depth and length under different geometric and hydraulic conditions. However, relatively few studies were conducted in order to analyze the effect of protection structures located in the stilling basin for the scour control. Recently, some experiments have been conducted at the University of Pisa for scour control downstream of block ramp in presence of rock sills located in the stilling basin. Their effects on the main geometric scour hole parameters were investigated. The present study wants to investigate the effect on scour process of other two sill types (continuous and dentated) located in the stilling basin in different spatial positions. Experiments were carried out with ramp slopes varying between 1V:4H to 1V:12H. Useful equations for the design of the stilling basin are proposed.