2017 American Society of Civil Engineers. Soil erosion is a major problem in civil engineering. It is involved in bridge scour, meander migration, levee overtopping, internal erosion of earth dams, surface erosion of embankments, and cliff erosion. The best way to predict the erodibility of a soil is to measure it directly on a site-specific basis by in situ testing in the field or by testing samples in the laboratory. The borehole erosion test (BET) is a new in situ soil-erosion test proposed to measure the erosion of the walls of a borehole while wet rotary drilling takes place. The increase in diameter of the borehole is measured with borehole calipers as a function of time and for a given flow velocity. The result is a profile of soil erodibility as a function of depth. Tests in clay and in sand conducted at the National Geotechnical Experimentation Sites at Texas A&M University are presented and compared with laboratory soil-erodibility tests with the erosion function apparatus (EFA) on samples taken from the same borehole. Computational fluid dynamics (CFD) numerical simulations of the velocity and shear stress field for the BET are also presented. The experimental and numerical results show the lessons learned and lead to an evaluation of the advantages and drawbacks of this new test.
