Influence of Non-Cohesive Soils with Induced Structural Heterogeneities on Internal Erosion Due to Suffusion

This paper presents an experimental study focused on the behavior of non-cohesive soils presenting structural heterogeneities subjected to internal erosion due to suffusion. The suffusion tests were performed by applying a downward seepage flow under multi-staged hydraulic gradient. Experiments were carried out at the scale of a soil sample. Soil samples with structural homogeneity and soil samples with structural heterogeneities were tested. Homogeneous soil samples were used as reference. Two heterogeneity configurations based on fines content (15% and 25%) and density index (ID = 0.1 and ID = 0.4) were tested. Measurement of flow velocity, total eroded mass and erosion rate were carried out. For the tested configurations, results show that soils with induced structural heterogeneities are more erodible than soils with homogeneous structure, independently of the fines content and the density index. The homogeneous specimens with low density index (ID = 0.1) are more erodible than those with medium density index (ID = 0.4).