Transport of sediment grains

Abstract

Having established in Chapter 5 some basic principles of fluid motion we now turn to the interaction between fluid motion and sediment grains. In the 1960s Bagnold gave the name loose-boundary hydraulics to this field of study to distinguish it from the hitherto more common analysis of the pure fluid motion alone. Initially we can distinguish two types of sediment flow boundary: granular-cohesionless and cohesive. The first type includes all boundaries made up of discrete solid grains which are kept in contact with adjacent grains purely by gravitational effects. The second type applies most commonly to clay mineral aggregates on mud beds where the tiny clay mineral flakes are mutually attracted by electrolytic forces which may be large compared to gravitational ones (Ch. 9).