Assessment of Coarse Soil’s Stability Towards Internal Erosion Case of Biskra’s Dam Soil

Internal erosion is a phenomenon that occurs in soils constituting hydraulic structures under the influence of internal flow. This erosion occurs because of pipe erosion which becomes widespread, leading in some cases to the rupture of the structure. Soils susceptible to piping, generally have particle size instability. This study aims to provide an empirical understanding of the initiation and development of erosion in coarse soil obtained near Biskra’s dam in Algeria. To assess the soil’s dispersiveness chemical analyses such as SAR and PS were conducted, as well as the particle size criteria were verified. The soil was examined in-depth using a double hydrometer test along with Crumb tests. A Hole Erosion Test (HET) device is developed to investigate the effect of certain parameters, such as the compaction degree and the hole diameter on internal erosion’s onset and progression. The results have shown the instability of the soil toward internal erosion given the considerably eroded particles. furthermore, an inverse relationship between the eroded particles mass and the degree of compaction and the initial hole’s diameter is observed.