Prediction of compressibility and hydraulic conductivity of soil-bentonite mixture

A mixture of bentonite and locally available soil is used as a clay liner material in the waste disposal site. Due to the high swelling and low hydraulic conductivity capacity, bentonite is preferred as a liner material. Since bentonite is available naturally its mineralogical composition and hence, its ability to swell and to provide a low value of hydraulic conductivity to the clay liner varies from source to source from which it has been procured. In this paper, a generalized approach is presented to predict the compressibility and hydraulic conductivity characteristics of the soil-bentonite mixture with the minimum input parameters. Four different methods to predict compressibility and three different methods to predict hydraulic conductivity of mixture has been discussed. Using the initial parameters such as the liquid limit, void ratio corresponding to the liquid limit water content, and overburden pressure the compressibility and hydraulic conductivity can be predicted effectively using these methods.