Incipient Transport of Fine Grains and Flakes by Fluids — Extended Shields Diagram

Abstract

Experiments on the incipient transport from flat sediment beds in water streams of four grades of fine cohesionless granular solids and six grades of fine cohesionless flaky solids are reported. The fine granular data are compared with data obtained from recent smaller-scale laboratory experiments, and all data are plotted on a Shields diagram. An extended Shields diagram which is applicable to cohesionless solids only is proposed. The fine flaky data are compared with collected data concerned with the incipient transport of coarse two-dimensional solids or flakes, and are again adapted to the Shields representation. The incipient transport fluid conditions for granular and flaky solids (which solids were chosen as being representative of extreme shape limits) are then contrasted.