A fully coupled elastic–plastic hydromechanical model for compacted soils accounting for clay activity

Abstract

SUMMARYA constitutive model, accounting for multiphase and multiscale coupling, is proposed for the water retention domain and the stress-strain response of compacted clayey soils. The model is based on a conceptual interpretation of the microfabric evolution of compacted soils along generalised hydromechanical paths, detected by means of mercury intrusion porosimeter tests. Multiphase coupling is provided by the mutual interaction between the mechanical and the hydraulic states. Multiscale coupling is introduced by a measure of the size of the aggregates, which influences both the retention and the stress-strain response, in the phenomenological constitutive equations. Model capabilities are verified by comparison with relevant experimental data from laboratory tests on compacted Boom clay and other selected experimental data on different compacted clayey soils.

A 3D Numerical Approach to Assess the Temporal Evolution of Settlement Damage to Buildings on Cavities Subject to Weathering

“…Despite considerable progress made in recent years in the study of the interactions between the soil (or rock) mass and the environment (including hydraulic, thermal and chemical coupling phenomena) (Alonso et al 1990;Cekerevac and Laloui 2004;Della Vecchia and Romero 2013;Gajo et al 2015;Gens 2010;Hueckel and Borsetto 1990;Jommi 2000; Uchaipichat and Khalili 2009), the application of advanced models to perform 3D numerical simulations to address such question is rare. In particular, chemo-hydro-mechanical (CHM)-coupled advanced numerical simulations are usually performed for 2D idealized problems to show the robustness of integration schemes or to simulate laboratory-scale boundary value problems (Fernandez-Merodo et al 2007;Tamagnini et al 2002;Tamagnini and Ciantia 2016).…”

Modeling swelling–shrinkage behavior of compacted expansive soils during wetting–drying cycles

“…Such models are therefore called double-structure models. Recent advances of double-structure models include the extension of model formulations to more general stress space or more complex stress paths (Sánchez et al 2005), and consideration for the coupling effect between thermal, mechanical, and hydraulic behavior (Alonso et al 2011;Gens et al 2011;Della Vecchia et al 2013;Mašín 2013). Beyond the scope of double-structure models, some constitutive models suitable for special practical cases were also developed for the sake of simplicity, in which the independent behavior of macrostructure and microstructure of expansive soils were not considered.…”

From saturated to unsaturated conditions and vice versa

“…This way of coupling mechanical and retention behaviour in the GCM contrasts with most other coupled constitutive models for unsaturated soils, as the majority of them describe the impact of mechanical behaviour on retention behaviour through total volumetric strain, rather than only plastic volumetric strain (e.g. [5,19,25,36,43,49,61]). The use of plastic volumetric strain ðe p v Þ to describe the influence of mechanical behaviour on water retention behaviour in the GCM, combined with the use of the Bishop's stress tensor as a stress state variable in the constitutive model, means that the GCM represents the occurrence of saturation/de-saturation in such a way that the predicted form and location of the normal compression line under saturated conditions are unique (unaffected by any previous stress history involving both saturated and unsaturated conditions).…”

“…Detailed descriptions of the mechanical and water retention aspects related to the evolving nature of the microstructure of compacted double-porosity clayey soils can be found elsewhere (e.g. [4,6,19,46,52]). Finally, anisotropy of soil behaviour is not considered in the paper, with the aim of focusing on saturation and de-saturation processes in soils without important direction-dependent response.…”