A water retention model accounting for void ratio changes in double porosity clays

Abstract This paper presents a constitutive model that predicts the water retention behaviour of compacted clays with evolving bimodal pore size distributions. In line previous research, differentiates between present inside saturated pores clay aggregates (the microstructure) and macrostructure). A new formulation is then introduced to account for effect macrostructural porosity changes on soil, which results in consistent evolution air-entry value suction volumetric deformations. Data from wetting tests three different active (i.e. MX-80 bentonite, FEBEX Boom clay), subjected distinct mechanical restraints, were used formulate, calibrate, validate proposed model. Results free swelling also modelled by using both double published single model, confirmed improvement predictions degree saturation approach. The might be applied, example, simulation hydromechanical engineered bentonite barriers underground nuclear waste repositories, where are structure under restrained volume conditions.