Numerical model of free swelling processes in compacted MX-80 bentonites

Abstract

This work proposes a formulation to simulate the swelling of compacted bentonites, focusing the analysis on the modelling of the increase of macrostructural void ratio generated by the destructuration of the microstructure under low confinement conditions. First, its formulation is described, highlighting its integration into a generalised constitutive model, which is able to describe the behaviour of compacted bentonites under very different conditions of stress, salinity and water content. After, its scope is assessed, comparing the model predictions with experimental results of free swelling tests performed under different salinity conditions. The results obtained are very satisfactory, especially considering that the proposed swelling model is based on only two material parameters.