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A laboratory investigation of the geotechnical properties of a marine clay saturated with a series of monovalent, divalent, and trivalent cations revealed large differences in behavior which depend on the exchangeable cations. The exchangeable cations employed in this study are sodium (Na), potassium (K), ammonium (NH4), magnesium (Mg), calcium (Ca), and aluminum (Al) in order of increasing valency. An increase in the valency of the adsorbed cations leads to an improvement in the geotechnical properties of the marine clay, while for a constant valency an increase in the hydrated radius of the adsorbed cations results in a lower rate of consolidation. Analysis of the results show that geotechnical properties are improved for the marine clay with cations having higher valency and smaller hydrated ionic radius in the adsorbed complex. The beneficial changes in properties can be attributed to the improvement in the efficiency of flocculation as the valency of the adsorbed cations increases and the hydrated io...

The type of cations present in the adsorbed double layer of any clayey soil can significantly control the soil's compressibility. This technical note examines the influence of exchangeable cations on the compressibility of a marine clay. An experimental investigation of the compressibility properties of marine clays with a series of monovalent, divalent, and trivalent cations revealed large differences in behavior. The exchangeable cations employed in this study were sodium (Na+), potassium (K+), ammonium (NH4+), magnesium (Mg2+), calcium (Ca2+), and aluminum (Al3+) in order of increasing valency. The results indicate that the compressibility properties are significantly affected by the valence and size of the adsorbed cations. An increase in valency leads to a reduction in compression index, and at a constant valency an increase in the hydrated radii of the adsorbed cations resulted in an increase in compressibility. Further, it has been found that preconsolidation pressure increases with valency of the ...

Lime has been successfully used as an additive to the soil to improve soil behavior. Cation exchange is considered to be one of the important reactions responsible for the improvement in the soil characteristics. This technical note presents the results obtained from model lime columns installed in a marine clay bed formed in the laboratory test tank. The diffusion of lime into the surrounding soil from the columns was confirmed through the increase in the values of pH and lime content (CaO) measured from a number of samples taken in between the columns. Further, there is an increase in the cation exchange capacity.