Study of the Anisotropic Properties of Argillite Under Moisture and Mechanical Loads

• Published in: Rock mechanics and rock engineering Vol. 46; no. 2; pp. 247 - 257
• Main Authors: Yang, Diansen, Chanchole, Serge, Valli, Pierre, Chen, Liufeng
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.03.2013; Springer; Springer Nature B.V
• Subjects: Anisotropy; Applied sciences; Building structure; Buildings. Public works; Civil Engineering; Clay minerals; Construction (buildings and works); Dehydration; Earth and Environmental Science; Earth Sciences; Exact sciences and technology; Geomorphology; Geophysics/Geodesy; Geotechnics; Hydration; Load; Moisture; Original Paper; Radioactive wastes; Rock; Rocks; Sedimentation; Soil mechanics. Rocks mechanics; Stresses; Underground structure; Haute-Marne; Champagne-Ardenne; Meuse; Lorraine; France; Europe; Dehydration and hydration; Anisotropic behavior; Shrinkage and swelling; Argillite; Hysteresis; DIC; Radioactive waste; Rock mechanics; Swelling; Hydration; Stress strain relation; Underground storage; Experimental device; Shrinkage; Dehydration; Experimental study; Anisotropic medium; Humidity effect; Underground construction; Microstructure
• ISSN: 0723-2632; 1434-453X
• DOI: 10.1007/s00603-012-0267-5

Due to various factors, such as sedimentation, layered morphology of clay minerals, in situ stress, etc., argillite rocks often exhibit anisotropic behavior. In order to study the anisotropic properties of the Callovo-Oxfordian (COx) argillite of the Meuse–Haute-Marne site in France considered as a possible host rock for high-level radioactive nuclear waste repository, a series of tests including uniaxial compression and dehydration and hydration at different constant applied stress levels are carried out. In this study, a specific setup combining moisture and mechanical loading with optical observation is used and it allows to continuously capture surface images from which the full-field strains are determined by using Digital Image Correlation techniques. The results show evidence of the mechanical and hydric anisotropy of the material. The anisotropy parameters are identified, assuming the studied argillite as transversely isotropic. The shrinkage and swelling depend on the applied stress and the angle with respect to the vertical direction of the mechanical load and the stratification plane, and this dependence is quantified. The non-linearity and the hysteresis observed during dehydration and hydration cycles are discussed.