LAUSR

Due to its low permeability, a clay liner is the main material used in solid waste disposal landfills. These liners exposed to various chemical, biological and physical events and would be affected by the resulting leachate which will change the shear strength parameters of compacted clay-bentonite liner (CCL). In this paper, the effect of four types of inorganic leachate’s components at concentrations of 2, 5 and 10%, leachate and deionised water on shear strength parameters of three CCLs with different plasticity index was investigated by performing a series of direct and vane shear tests. The experimental results show that in both direct and vane shear tests, by addition of soluble salts of single-valence cations and leachate provided from them up to 2%, the undrained shear strength of clay-bentonite liners increased. With further increase in contaminants, the shear strength decreased. The variation of undrained shear strength for clays by the addition of soluble salts of bivalence cations is more intricate. Also, it can be found that, the effect of contaminants on shear strength of clays is more significant in clays with medium plasticity index.