Local Scour Downstream of bed protection works

Abstract

This paper describes experimental results of local scour downstream of a bed protection work with hollow squared blocks under a dynamical equilibrium condition of bed load. Variations of profiles and the maximum depths of scour holes with time were discussed, and compared with those under a static equilibrium condition and experimental results of a bed protection work with smooth bed. Flow characteristics, such as, velocity distributions, bed shear stress and pressure on the scoured bed were also measured at several stages of scour. Non-equilibrium caluculations of bed load using the bed shear stress measured could simulate well the variations of scour hole in the early stage of the scour.