Compression Behavior of the Soils Subjected to Seepage Erosion

Seepage erosion, driven by escalating hydraulic gradients within the soil matrix, leads to seepage-induced deterioration, posing a significant hazard to the structural integrity of embankments. The compression behavior of embankments is a crucial characteristic that requires attention. Understanding how this behavior evolves under various extents of seepage erosion is essential for evaluating embankment stability. Infiltration tests were conducted on an internally unstable clay and sand under water heads below the critical hydraulic gradient. Subsequent compression tests on the resultant eroded samples assessed how erosion extent influences subsequent compression behavior. The results indicate that internally unstable sand exhibits a reduced critical hydraulic gradient and increased susceptibility to seepage-induced damage compared to internally unstable clay. Compression curves for internally unstable soils subjected to different extents of seepage erosion follow linear trends under high-stress conditions, with negligible variation in associated compression indices (λ). However, the normal consolidation lines (NCL) for soils subject to varying extents of seepage erosion do not align; instead, they progressively shift downward as erosion intensifies. This indicates that seepage erosion profoundly alters soil structure, rendering soils more susceptible to compression and subsequent gravitational settlement as the extent of erosion increases. Understanding the relationship between soil erosion and subsequent compression behavior is crucial for predicting embankment seepage failure in advance.