A prediction method for swelling deformation of bentonite and its sand-mixtures in salt solution

Abstract

The swelling deformation tests of Tsukinuno bentonite and its sand-mixtures were performed in distilled water and NaCl solution with different concentration. The results showed the swelling strain decreased with the increase in the vertical pressure, the salt concentration, and the sand content in the mixtures. The swelling properties of the bentonite can be characterized by a unique fractal e m -p e relation, where the effective stress p e incorporating with osmotic suction was applied to take the effect of salinity into consideration. And the coefficient K, as the physical constant of bentonite can be estimated by diffuse double layer (DDL) model in the case of distilled water. The applicability of the fractal e m -p e relation has been confirmed by comparing the predicted results with swelling deformation tests on Tsukinuno bentonites in various salt solution concentrations.