Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.3390/min16030279 |
Licence  |
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| Title (Primary) | Hydro-mechanical modelling of anisotropic deformation and failure behaviour of Opalinus Clay under saturated and unsaturated conditions |
| Author | Radeisen, E.; Shao, H.; Hesser, J.; Wang, W.
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| Source Titel | Minerals |
| Year | 2026 |
| Department | ENVINF |
| Volume | 16 |
| Issue | 3 |
| Page From | art. 279 |
| Language | englisch |
| Topic | T8 Georesources |
| Keywords | Opalinus Clay; hydro-mechanical behaviour; anisotropic constitutive modelling; bedding-controlled plasticity; OpenGeoSys |
| Abstract | Opalinus Clay (OPA) is a key host rock for the geological disposal of high-level radioactive waste in Switzerland and is also under investigation in Germany. Reliable prediction of the long-term performance of deep geological repositories requires constitutive models capable of capturing the coupled hydro-mechanical (HM) behaviour of the host rock, including mechanical anisotropy, strain-dependent stiffness, suction effects, and stress-dependent failure. This study presents a hydro-mechanically coupled constitutive model incorporating anisotropic yield behaviour, hardening/softening, and strain-dependent permeability. The model is calibrated against laboratory triaxial, Brazilian tensile strength (BTS), and uniaxial compressive strength (UCS) tests on OPA, with bedding orientations between 0° and 90°. Implemented in OpenGeoSys (OGS), the model represents bedding-controlled plastic anisotropy using a microstructure tensor approach. The simulations reproduce key experimental trends relevant to repository-induced perturbations, including bedding-dependent strength and stiffness, suction effects on UCS, and the orientation-dependent tensile strength observed in Brazilian tests. Remaining discrepancies under high confining stress indicate the need for improved regularization and dilatancy formulations. Overall, the proposed framework provides a robust building block for HM process modelling and long-term safety assessments of deep geological repositories. |
| Radeisen, E., Shao, H., Hesser, J., Wang, W. (2026): Hydro-mechanical modelling of anisotropic deformation and failure behaviour of Opalinus Clay under saturated and unsaturated conditions Minerals 16 (3), art. 279 10.3390/min16030279 |
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