Author(s): Gensheng Zhao; Paul J. Visser; Hanj. K. Vrijling
Linked Author(s): Gensheng Zhao, Paul Visser
Keywords: Erosion process; Undisturbed clay; Turbulent boundary-layer flow; Incipient stress
Abstract: This paper describes the hydrodynamic erosion process of undisturbed clay due to the turbulent flow, based on theoretical analysis and experimental results. The undisturbed clay has the unique and complicated characteristics of cohesive force among clay particles, which are highly different from disturbed clay and non-cohesive sand. Based on momentum equilibrium, the critical incipient velocity is derived from the forces of particle weight under water, cohesive force among particles around the clay particle, uplift force and drag force. Via the turbulent boundary layer flow theory, the critical stress can be connected with these forces. The formulae for the incipient stress and the critical velocity have been calibrated and validated with the results of undisturbed clay tests. A new formula for the erosion rate is proposed. The study gives a new insight into the erosion process of undisturbed clay and the resulting sediment transport.
Year: 2011