N° d’ordre :…2421…… THESE présentée pour obtenir LE TITRE DE DOCTEUR DE L’INSTITUT NATIONAL POLYTECHNIQUE DE TOULOUSE École doctorale : Sciences de l’Univers de l’Environnement et de l’Espace Spécialité : Sciences de la terre et environnement Par M…Israel CAÑAMON VALERA Titre de la thèse ANALYSE ET MODELISATION DES PHENOMENES COUPLES THERMO-HYDRO-MECANIQUES EN MILIEUX FRACTURES 3D Soutenue le 30/11/2006 devant le jury composé de : M.Prof. Dr.-Ing. Ghislain de MARSILYRapporteur M.Prof. Dr.-Ing. Jesus CARRERARapporteur M.Prof. Dr.-Ing. Pedro R. OYANGURENMembre M.DR CNRS Dr.-Ing. Michel QUINTARDMembre M.DR CNRS Dr. Alain MANGINMembre M.Prof. Dr.-Ing. Rachid ABABOUDirecteur M.Prof. Dr.-Ing. Fco. Javier ELORZADirecteur M.Prof. Dr.-Ing. Philippe RENARDInvité
UNIVERSIDAD POLITÉCNICA DE MADRID (D-15) Tribunal nombrado por el Magfco. Y Excmo. Sr. Rector de la Universidad Politécnica de Madrid, el día ………….. de ………….. de 200…….. Presidente:.
Realizado el acto de la defensa y lectura de la Tesis el día …… de …………... de 200… en la E.T.S.I. / Facultad ………………………………………………. EL PRESIDENTE LOS VOCALES EL SECRETARIO
ACKNOWLEDGEMENTS This work is part of the research of the FEBEX I and II projects, co-funded by ENRESA and the European Commission under contract numbers FI4W-CT95-0006 and FIKW-CT-2000-0016 of the IV and V Mark Programs respectively. I would like to thank specially my two thesis directors, Fco. Javier Elorza and Rachid Ababou, for all the personal and scientific support that have given to me during the thesis studies. I would like to thank, also, all the outstanding professors and researchers that have helped me in specific topics at some point during the research, and excusing myself if I forget someone in the list: Alain Mangin, Carlos Paredes, Ruxandra Nita, Enrique Chacón, Ángel Udías, Ramón Rodríguez, Ultano Kindelán, Santiago de Vicente, Fernando Huertas, Pascual Farias, etc. And thanks to the Departamento de Matemática Aplicada y Métodos Informáticos of the E.T.S.I.M. and its staff to give me the opportunity to accomplish my doctoral studies within its framework.
ABSTRACT Analysis and Modeling of Coupled Thermo-Hydro-Mechanical Phenomena in 3D Fractured Media. This doctoral research was conducted as part of a joint France-Spain « cotutelle » PhD thesis in the framework of a bilateral agreement between two universities, the Institut National Polytechnique de Toulouse (INPT) and the Universidad Politecnica de Madrid (UPM). It concerns a problem of common interest at the national and international levels, namely, the disposal of radioactive waste in deep geological repositories. The present work is devoted, more precisely, to near-field hydrogeological aspects involving mass and heat transport phenomena. Thefirst partof the work is devoted to a specific data interpretation problem (pressures, relative humidities, temperatures) in a multi-barrier experimental system at the scale of a few meters – the “Mock-Up Test” of the FEBEX project, conducted in Spain. Over 500 time series are characterized in terms of spatial, temporal, and/or frequency/scale-based statistical analysis techniques. The time evolution and coupling of physical phenomena during the experiment are analyzed, and conclusions are drawn concerning the behavior and reliability of the sensors. Thesecond partof the thesis develops in more detail the 3-Dimensional (3D) modeling of coupled Thermo-Hydro-Mechanical phenomena in a fractured porous rock, this time at the scale of a hundred meters, based on the data of the “In-Situ Test” of the FEBEX project conducted at the Grimsel Test Site in the Swiss Alps. As afirst step, a reconstruction of the 3D fracture network is obtained by Monte Carlo simulation, taking into account through optimization the geomorphological data collected around the FEBEX gallery. The heterogeneous distribution of traces observed on the cylindrical wall of the tunnel is fairly well reproduced in the simulated network. In asecond step, we develop a method to estimate the equivalent permeability of a many-fractured block by extending the superposition method of Ababou et al.  to the case where the permeability of the rock matrix is not negligible (matrix permeability may embody some finer fracturing in addition to pore space). When fracture flow is complemented by significant matrix permeability, it may be possible to avoid empirical connectivity-based corrections, which are used in the literature to account for non-percolation effects. The superposition approach is also applied here to coupled Hydro-Mecanical problems to obtain the equivalent coefficients of the 3D fractured medium, including the permeability tensor, but also elastic stiffness or compliance coefficients, as well as pressure-strain coupling coefficients (Biot). Finally, these results are used to develop a continuum equivalent model for 3D coupled Thermo-Hydro-Mechanics, including: hydro-mechanical coupling via tensorial Biot equations (non-orthotropic), a darcian flow in an equivalent porous medium (anisotropic permeability), as well as thermal stresses and heat transport by diffusion and convection, taking into account the thermal expansivity of water. Transient simulations of the excavation of the FEBEX gallery, and of the heating due to hypothetical radioactive waste canisters, are conducted using the Comsol Multiphysics ® software (3D finite elements). The results of numerical simulations are analyzed for different cases and different ways of stressing the system. Finally, preliminary comparisons of simulations with time series data collected during the “In-Situ Test” of FEBEX yield encouraging results.