Theoretical description of embankment erosion owing to overflow

Abstract

This paper presents a theoretical description of embankment erosion owing to overflow based on experimental results from the viewpoint of erosion. Experiments in the laboratory, where silty sand was used to make a model of an embankment, were carried out to observe and confirm the failure process of an embankment resulting from overflow. The experimental results were quite similar to those in previous studies by other researchers. Understanding the way in which a Froude-critical point migrates during overtopping failure, and then stops, is essential to modelling the failure mechanism. The migration of the Froude-critical point involves the development of erosion and the vertical drop, or headcut, that is caused when it stops. Shallow water equations and an equation governing the change in elevation of the erosional surface are used to describe the erosion of the embankment. The theory allows the profiles of an embankment during overtopping failure to be partially determined under the condition of imposed parameters. In addition, considering the Froude-critical point's migration and suspension, the time required for the complete failure of an embankment, that is the embankment break, can be estimated.