Modelling the behaviour of unsaturated non-active clays in saline environment
Journal article, 2021

The chemical composition of pore fluid and matric suction rule the mechanical behaviour of soils. In case of clays, their fabric changes in line with those variables. Since both the increase in matric suction and salinity cause a transition from an open to a close microstructure of low and medium activity clayey materials, a unique framework could tackle problems where salinity and saturation changes are expected. This paper presents a simple elasto-plastic model capable of reproducing the behaviour of unsaturated clayey soils in saline environments. Changes in the pore fluid composition are addressed through the use of osmotic suction as a variable. The proposed model extends the Barcelona Basic Model for partially saturated soils to consider the effect of osmotic suction. The model, implemented in the Thebes code, is calibrated for Boom Clay. The reproduced tests include mechanical loading at different matric and osmotic suctions in oedometric conditions, as well as more complex chemo-mechanical stress paths. Despite the simplicity of the formulation, the agreement between the experimental results and the simulations is encouraging. It seems that the modelling approach addresses the most important features of partially saturated soils with saline pore fluid which are slightly or moderately expansive.

Osmotic suction

Matric suction

Constitutive relations

Barcelona Basic Model

Unsaturated clays

Clay microstructure


Giulia Scelsi

Polytechnic University of Milan

Ayman Abed

Aalto University

Chalmers, Architecture and Civil Engineering, Geology and Geotechnics

Gabriele Della Vecchia

Polytechnic University of Milan

Guido Musso

Polytechnic University of Turin

W. Solowski

Aalto University

Engineering Geology

0013-7952 (ISSN)

Vol. 295 106441

Subject Categories

Soil Science

Applied Mechanics

Environmental Sciences related to Agriculture and Land-use



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