Implementation of an unsaturated anisotropic clay model (JMC-Clay) in the coupled hydro-mechanical framework of CODE_BRIGHT
Implementation of an unsaturated anisotropic clay model (JMC-Clay) in the coupled hydro-mechanical framework of CODE_BRIGHT
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The engineering response of soft clays is governed by fabric anisotropy developed during their depositional history, which significantly influences stiffness, strength and yielding characteristics. When these soils are additionally subjected to changes in water content, capturing the coupled effects of anisotropy and partial saturation within a unified constitutive framework becomes essential. The JMC-Clay model, recently developed for soft organic clays, extends the SANICLAY framework by introducing a flexible yield surface shape and an enhanced rotational hardening rule with Lode-angle dependence. In this work, the model is extended to unsaturated conditions using skeleton stress as the constitutive stress variable and a hysteretic water retention curve for hydro-mechanical coupling. The extended model has been implemented in the finite element platform CODE_BRIGHT for coupled thermo-hydro-mechanical analysis. Saturated verification is performed by comparing a single-element driver with fully coupled boundary value problem simulations of triaxial tests. For the unsaturated validation, the complete wetting-drying-wetting cycle reported by Romero and Jommi (2008) on compacted Boom clay is simulated, demonstrating the model's ability to reproduce anisotropic collapse, progressive fabric erasure, and irreversible shrinkage.
Ching. Yu Chao; S. Muraro; C. Jommi
International Conference on Advances and Innovations in Soft Soil Engineering (ICAISSE2026)
Constitutive, Numerical, and Machine Learning Modelling
https://doi.org/10.53243/ICAISSE2026-78