A new approach to quantify the anisotropy of hydromechanical strains in clay-rock at the gallery scale
| Autor: | Justo Cabrera, Philippe Cosenza, Valéry Valle, Stephen Hedan |
|---|---|
| Přispěvatelé: | École Nationale Supérieure d'Ingénieurs de Poitiers (ENSI Poitiers), Université de Poitiers, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Photomécanique et analyse expérimentale en Mécanique des solides (PEM), Département Génie Mécanique et Systèmes Complexes (GMSC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Institut de Radioprotection et de Sûreté Nucléaire (IRSN) |
| Rok vydání: | 2018 |
| Předmět: |
Digital image correlation
Bedding Aspect ratio Scale (ratio) Poromechanics Hydromechanical strains Context (language use) Soil science [CHIM.CATA]Chemical Sciences/Catalysis 02 engineering and technology 010502 geochemistry & geophysics Geotechnical Engineering and Engineering Geology 01 natural sciences 020303 mechanical engineering & transports 0203 mechanical engineering Hydric soil Tournemire clay rock Anisotropy measurement Anisotropy Geology 0105 earth and related environmental sciences |
| Zdroj: | International Journal of Rock Mechanics and Mining Sciences International Journal of Rock Mechanics and Mining Sciences, Pergamon and Elsevier, 2018, 111, pp.45-53. ⟨10.1016/j.ijrmms.2018.07.004⟩ |
| ISSN: | 1365-1609 1873-4545 |
| Popis: | International audience; We describe a new method to quantify the anisotropy ratio of hydric strains acquired at the gallery scale and over a period of at least one year. This method was applied in the context of an investigation conducted on a gallery front of the Experimental Station of Tournemire (France), which was subjected to a natural seasonal cycle. Our approach was based primarily on a new algorithm for Digital Image Correlation, known as H-DIC, which can accurately locate desiccation cracks and extract fifteen uncracked blocks with quantified sub-vertical and sub-horizontal strains.The values of the anisotropy ratio of hydric strains (i.e., the ratio of the sub-vertical strains to the sub-horizontal strains, or the ratio of the strains perpendicular to the bedding to those parallel to the bedding) are in the range of [2.84–5.35], with a mean value close to 4.2.The anisotropy ratio for the hydric strains appears to be independent of the natural cycle (i.e., hygrometry) present in the gallery. This observation is supported by a theoretical estimation of this anisotropy ratio, which suggests that the poroelastic parameters of clay rock are insensitive to climatic changes or that theirs evolutions roughly cancel each other out. With regard to geometrical patterns (area, width, height, aspect ratio and orientation) calculated for the uncracked blocks, the anisotropy ratio of the hydric strains does not depend on the area of these uncracked blocks.Moreover, a literature review shows that the values of the anisotropy ratio for the hydric strains determined in this study are significantly larger than those obtained at the laboratory scale on undamaged samples or estimated from a theoretical relationship established in a poroelastic framework. These comparisons strongly suggest that damage to clay rock existing on the gallery front contributes to a significant increase in the anisotropy ratio of the hydric strains. |
| Databáze: | OpenAIRE |
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