Development of a simplified theoretical model to determine erodibility of compacted soil in hole erosion test based on fluid energy transformation

Erodibility assessment of soil by hole erosion test (HET) is popular due to its advantages of being economical, rapid, simple procedure and better control over soil properties. Modelling the erosion process in HET is vital for interpreting the measurements and unambiguous quantification of the erodibility of compacted soil in geotechnical infrastructures. This study developed a new theoretical model by considering power (instead of shear stress) to describe the concentrated leak erosion processes of compacted soil in HET using Bernoulli’s Energy equation and work-energy principle. The model accounts for soil self-weight, fluid flow rate, fluid energy transformation, hole enlargement, and compaction state of soil for obtaining the soil erodibility. For this purpose, a relationship was developed between erosion rate and fluid energy rate. A new analytical equation was proposed for determining the temporal hole enlargement in HET as well as the erodibility of soil without the knowledge of the piezometric head. The theoretical and analytical model was validated by (a) performing HETs with repetitions and (b) comparing with the existing interpretation method. The proposed theoretical and analytical methods showcased similar results in terms of the erodibility of soils under varying hydraulic conditions. The use of the new models considerably simplifies the interpretation of HET and addresses the problem of unambiguous estimation of soil erodibility.