Author(s): Stefano Pagliara; Michele Palermo; Sahameddin Mahmoudi Kurdistani; Leila Sagvand Hassanabadi
Keywords: Grade control structures; Non-dimensional profiles; Plunging jets; Scour morphology
Abstract: One of the main problem in the presence of hydraulic structures is the localized scour phenomenon occurring downstream of them. In particular, the analysis of the scour processes is of fundamental importance for a correct design of any hydraulic structure, as the hydraulic functioning can be guaranteed only if the structure itself is stable. Thus, the knowledge of the scour hole shape and characteristics, varying both structure configurations and hydraulic parameters, has been widely investigated during past decades and still represents one of the main topic for hydraulic engineers. Nevertheless, the conspicuous technical literature dealing with erosive phenomena generally focuses on single hydraulic structures, highlighting the performance in terms of energy dissipation and analyzing their behavior in terms of scour process due to either plunging or submerged jets. But, few attempts are present in literature which analyze similitudes in the scour hole morphology downstream of different hydraulic structures. Namely, this paper aims to develop a critical analysis of the localized scour phenomena downstream of both dams and grade control structures resulting in a comparison of non-dimensional profiles of the scour hole in various hydraulic conditions. In particular, non-dimensional profiles due to both aerated and non aerated plunging jets were compared with those occurring in the stilling basing in the presence of block ramps, rock grade control structures, stepped gabion weirs, cross-vane structures and vertical crossing jets. Both similitudes and differences are discussed and non-dimensional predicting equations are compared and analyzed.