Structural defence for plunge pool scour

Plunge pool scour is a major topic in presence of hydraulic structures that foresees the production of jets. The scour hole is a function of several variables including the tailwater, the densimetric Froude number, the sediment granulometry, the water discharge. The maximum scour depth is of great interest in the design process. Aim of the paper is to analyze the effect of structures, inserted in the scour hole, in order to mitigate the scour geometry. About 300 tests have been carried out in the Hydraulic laboratory of the University of Pisa (Italy) in order to assess the advantages and the problems connected with the insertion of a rigid structures in the river bed. In this paper a first description of the phenomena is presented