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AbstractAbstract
[en] This Ph-D thesis investigates the potential of clay rocks for deep geological disposal of radioactive waste. Underground excavations are responsible in their vicinity a region, where the clay-rock is damaged or disturbed. This region must to be characterized to ensure the safety of repositories. The extension of the excavation damaged zone (EDZ) and its evolution over time have been investigated thought electrical resistivity and induced polarization methods from three galleries belonging to the French Institute of Radioprotection and Nuclear Safety (IRSN)'s experimental underground research laboratory of Tournemire (Aveyron, France). Time domain induced polarisation indicates the presence of mineralization (e.g., especially pyrite) located in the structural discontinuities such as tectonic fractures (mm-cm), tectonic fault (m) and calcareous nodules (cm). Combined electrical resistivity and Induced Polarization methods show the possibility to delineate textural changes associated to desaturation of the clay-rock induced by the ventilation of galleries. The impact of the desaturation is particularly observed on the gallery's walls. In addition, Spectral Induced Polarization (SIP) tomography results can be used to discriminate the responses of the de-saturated zones from the fractured zones. We have performed laboratory experiments (in the range 1.4 mHz - 12 kHz) using saturated unconsolidated sand-clay mixtures. The results illustrate that the amplitude of polarization is strongly affected by the surface properties of these mixtures (e.g., cation exchange capacity, specific surface area) and by the volumetric clay content. However, the amplitude of polarization is independent of the concentration of electrolyte. The SIP response is also strongly sensitive to the mineralogy of the clays. (author)
Original Title
Caracterisation des heterogeneites texturales et hydriques des geomateriaux argileux par la methode de Polarisation Provoquee: Application a l'EDZ de la station experimentale de Tournemire
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Source
25 Mar 2011; 432 p; [270 refs.] ; Available from the INIS Liaison Officer for France, see the 'INIS contacts' section of the INIS website for current contact and E-mail addresses: http://www.iaea.org/INIS/contacts/; These Geophysique Appliquee
Record Type
Report
Literature Type
Thesis/Dissertation
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Country of publication
ARGILLITE, BENTONITE, ELECTRODES, GEOLOGIC FAULTS, HEAT TREATMENTS, INDUCED POLARIZATION LOGGING, ION EXCHANGE MATERIALS, KAOLINITE, MINERALOGY, NONDESTRUCTIVE ANALYSIS, PYRITE, RESISTIVITY LOGGING, ROCK MECHANICS, SALINITY, SHAFT EXCAVATIONS, SITE CHARACTERIZATION, SPECIFIC SURFACE AREA, UNDERGROUND FACILITIES, WATER SATURATION
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