Thm analysis of argillaceous rocks with application to nuclear waste underground storage
- Autores: Saeed Tourchi
- Directores de la Tesis: Antonio Gens Sole (dir. tes.), Jean Vaunat (codir. tes.)
- Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2020
- Idioma: español
- Materias:
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- Resumen
Argillaceous rocks (Stiff sedimentary clays) provide the geological background to many civil engineering projects. In recent years, interest in these types of material has increased, because they are being considered as potential host geological media for underground repositories of high-level radioactive waste (HLW). The possible use of these types of clay as geological hosts for radioactive waste has prompted the construction of several underground laboratories. Among the very different topics addressed in the Underground Research Laboratories (URLs), the thermo-hydro-mechanical (THM) behaviour of the host rock is the one that most concerns the present research. In situ observations have revealed a considerable number of coupled THM processes in the operation of an HLW repository.
In this context, the main objective of the present study is to describes the performance, observations and interpretation of the full-scale in situ heating test conducted on Callovo-Oxfordian (COx) claystone in the Meuse / Haute-Marne URL simulating a heat-emitting, high-level radioactive waste disposal concept. The test is fully instrumented, and attention is focused on the near-field region's the THM behaviour consisting of the sleeve surrounding the heater and the host rock. The interpretation of the test is assisted by the performance of a coupled numerical analysis based on a coupled formulation incorporating the relevant THM phenomena. The calculations have used a reference isothermal constitutive model especially developed for this type of material. The reference model later has been extended to non-isothermal condition by incorporating thermal dependency of strength parameters and stiffness. The thermomechanical model has been successfully used in the simulation of triaxial tests on COx claystone. The numerical analysis performed has proved able to represent the progress of the experiment very satisfactorily. The performance and analysis of the in-situ test has significantly enhanced the understanding of a complex THM problem and have proved the capability of the numerical formulation and non-isothermal constitutive model to provide adequate predictive capacity.
