On modelling of the hole erosion test

A phenomenon called «piping» often occurs in hydraulics works, involving the progression of a continuous channel between the upstream and the downstream side. The hole erosion test is commonly used on the laboratory to quantify the rate of piping erosion [1]. However, few attempts have been made to model these tests. The purpose of this paper is to propose a useful model for the interpretation of the hole erosion test. From the equations of diphasic flow with diffusion [2], and the equations of jump with erosion at the fluid/soil interface, a piping model is developped. A characteristic time of internal erosion process is proposed, as a function of hydraulic gradient, and soil, water and erosion parameters. Simulation of the hole erosion test reveals an exponential scaling with time for the increase of the radius. A comparison with experimental data validates the model for test interpretation.