Anisotropic hydro-viscoplastic modelling of a drift at the Meuse/Haute-Marne URL

The Meuse/Haute-Marne underground research laboratory was built in the Callovo-Oxfordian (COx) clay formation for the purpose of assessing the feasibility and safety of a deep geological formation to host an industrial radioactive waste repository (Cigeo project) in France. Some observations related to the drifts oriented in the direction of the major horizontal stress remain to be theoretically and numerically understood. In order to contribute to the understanding of the hydromechanical behaviour of the COx claystone, an elasto-viscoplastic model with transient creep was developed, including the inherent elastic and hydraulic anisotropies. Comparison within situmeasurements was made, with encouraging results.

Automated summary

The Meuse/Haute-Marne underground research laboratory was built in France to assess the feasibility and safety of a deep geological formation for hosting an industrial radioactive waste repository. The study found that further understanding is needed for observations related to the direction of the major horizontal stress. By developing an elasto-viscoplastic model with transient creep and inherent anisotropies, the hydromechanical behavior of the COx claystone can be better understood.