The effects of lime, bentonite and nano-clay on erosion characteristics of clay soils
Piltan Tabatabaie Shourijeh, Abbas Soroush, Amir-Hossein Daneshi-Sadr
Abstract
Erosion, both surficial and internal, presents risks to performance and stability of earth dams, dikes, and water barriers. The consequences and severity of erosion incidents are amenable to soil erodibility. This study investigates the efficiency of additives/stabilizers in modifying soil erosion characteristics. Erosion parameters, namely coefficient of soil erosion, critical shear stress, and erosion rate index, for five very fine, highly erodible clay/silt soils treated with additives, that is sodium bentonite, calcium bentonite, hydrated lime, silica fume and a Nano clay, are determined via the Hole Erosion Test (HET). Also, alterations in plasticity index and compaction properties for treated soils are examined. Experimental findings suggest that hydrated lime, which delivers an ample amount of Ca2+, reduces erodibility mainly be increasing critical shear stress, while calcium bentonite which encompasses structural Ca cations, enhances erosion resistance by decreasing the coefficient of soil erosion. Besides, sodium bentonite does not improve the erosion resistance. From a practical viewpoint soil treatment with hydrated lime and calcium bentonite lowers the likelihood of concentrated leak erosion initiation and decelerates the progression of piping.