Development of a new submersible test to characterise the erosion of soils and sediments

Understanding the mechanism and behavior of the scour process is a most challenging subject. One part of this challenge is the in situ measurement of soil and sediment sensitivity to erosion (in undisturbed and submersible conditions). To improve this understanding, a new test, the Wheel Erosion Test (WET), was developed. It consists of a wheel rotating upon a layer of sediments located in an aquarium filled in with water. The rotating speed of the wheel and the distance to the sediment bed are the main control parameters. If the bed shear stress produced by the wheel is sufficient, grains are eroded and a scour hole is observed. The dimensions of the scour hole (length, width and depth) can be determined by video camera and acoustic measurements allowing the quantification of erosion strength. A first parametric study on Fontainebleau sand validating the principle of the WET is reported.