Modelling the erosion rate of chemically stabilized soil incorporating tensile force – deformation characteristics

Abstract

To evaluate the safety of embankment dams, it is necessary to estimate the erosion rate based on common geotechnical properties such as shear and tensile strength. However, the empirical expressions that are currently available in the literature for this purpose are often inadequate. In this paper, an analytical model is developed to model the erosion of a soil capturing its tensile behaviour based on the law of energy conservation. The erosion rate can be determined using the proposed model if the tensile force – deformation characteristics, dry density, mean particle diameter, and mean flow velocity are known. The proposed model is semi-empirical and can be validated with experimental results obtained from the novel process simulation apparatus for internal crack erosion (PSAICE) designed and built at the University of Wollongong, Australia. All tests were conducted on erodible silty sand stabilized with cement and lignosulfonate. The model validation clearly indicates that only a fraction of the energy (efficiency index) from the water stream is effectively used for erosion.