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عنوان فارسی مقاله:
مطالعه چند مقیاسی تکامل و تغییر شکل شکستگی نمونه سنگ سفال در معرض خشک شدن
عنوان انگلیسی مقاله:
Multi-scale study on the deformation and fracture evolution of clay rock sample subjected to desiccation
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
Clay rocks have been considered as potential repositories for high-level radioactive wastes in several industrial countries. Among the critical issues related to the long-term safety assessment of such geological repositories, the study of the so-called excavation damaged zone (EDZ) is particularly important. The initiation and extension of the EDZ are governed by many parameters (Bossard et al., 2002; Tsang et al., 2005; Blüming et al., 2007) including the material properties of the rock, such as the material anisotropy; the initial stress field; the existence of natural fracture zones in the rock mass; the geometry of the gallery; and the hydric state in the gallery. With regard to the hydric state in the gallery, fractures associated with the desaturation of argillaceous medium have been observed on gallery fronts in several underground research laboratories, such as the experimental platform of Tournemire (Cabrera et al., 2001; Matray et al., 2007) and the Mont Terri Laboratory (Möri et al., 2010). This hydric fracturing process is evidenced in situ by sub-horizontal cracks spaced at several decimeters on all vertical walls in contact with ambient air. In winter (dry state), the corresponding crack apertures can reach a few millimeters, whereas these cracks are closed in summer (wet state). These sub-horizontal cracks induced by desiccation are parallel to the bedding planes, suggesting that they are partially controlled by sedimentological patterns (e.g., vertical differences in sediment grain size and mineral composition or organization). Recent studies have revealed other types of sub-horizontal desiccation cracks (Hedan et al., 2014; Valle et al., 2015) with a distance of approximately 64–100 mm and sub-vertical cracks (Hedan et al., 2014) connected to the subhorizontal cracks with features identical to those of the sub-horizontal cracks. These observations of clay rock damage induced by drying have been obtained in the field using the digital image correlation (DIC) technique. At a much lower scale, Wang et al. (2013, 2014) applied the DIC algorithm directly on back-scattered electron images (128 × 111 μm2 ) from an environmental scanning electron microscope (ESEM). By means of this combination of ESEM and DIC techniques, the swelling/shrinkage and more generally the hydromechanical behavior of the Callovo-Oxfordian clay rock located in the Paris basin was investigated at the micrometer scale. Their observations revealed two micromechanisms. First, the local swelling or shrinkage is strongly anisotropic in the plane perpendicular to the bedding planes (with the major swelling direction normal to the bedding plane). Second, a complex network of microcracks with typical openings of approximately 1 μm was detected in both the wetting and drying paths. These microcracks were located in the bulk of the clay matrix and/or at quartz/carbonate inclusion– clay matrix interfaces (Wang et al., 2014). However, these previous observations were all obtained at very different space scales, and the phenomenological links or causal relationships between them are unclear. The relationships between these observations acquired at different scales could facilitate the identification of the micromechanisms governing desiccation cracking. Following this perspective, the main objective of this laboratory investigation was to design an original methodology for providing new observations and correlations between hydric strains, desiccation crack apertures and state variables (relative humidity (RH) and water content) at the millimeter and centimeter scales. These scales are rarely investigated in the context of clay rocks. This methodology is based on the combination of a new experimental setup and a new DIC algorithm (H-DIC). On the same sample, this combination allows the measurement of the kinematic field and patterns for the two considered scales (i.e., millimeter and centimeter scales). The results were compared with those previously obtained at the micrometer and gallery scales to provide physical constraints to improve the models and the understanding of desiccation cracking in clay rocks.
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کلمات کلیدی:
Multi-scale study on the deformation and fracture evolution of clay rock ... isi-dl.com/item/289577 Multi-scale study on the deformation and fracture evolution of clay rock sample subjected to desiccation. sciencedirect.com ... [PDF]Multi-scale investigation of fracture apertures in clay rock subjected to ... repository.tudelft.nl/islandora/object/uuid:49ffcc2c-72b0-4a30-b939.../download In the laboratory, the desiccation fracture apertures in Tournemire clay rock ... of Tournemire clay rock (Aveyron, France) was used as the sample in this study. The .... In free conditions of deformation, the results highlight two important steps of ... and fracture evolution of clay rock sample subjected to desiccation, Accepted for ... Landslide Science and Practice: Volume 3: Spatial Analysis and Modelling https://books.google.com/books?isbn=3642313108 Claudio Margottini, Paolo Canuti, Kyoji Sassa - 2013 - Nature Volume 3: Spatial Analysis and Modelling Claudio Margottini, Paolo Canuti, Kyoji ... process and regularity of the deformation and fracture of stratified rock mass ... parameter table Sandstone Clay Density (g/cm3) Deformation modulus (104 ... Analysis of Vibration Trace and Deformation and Fracture Evolution Process ... [PDF]Study on the Progressive Failure Characteristics of Longmaxi Shale ... www.mdpi.com/1996-1073/10/3/303/pdf by X Li - 2017 Mar 3, 2017 - treatments are usually essential in the development of shale gas [5–7]. ... the fractured rocks are observed using CT after failure occurred, the failure ... study the progressive deformation-failure process of compact shale due to ... The Internal Structure of Fault Zones: Implications for Mechanical ... https://books.google.com/books?isbn=1862392536 Christopher A. J. Wibberley - 2008 - Science by careful observation of the evolution of peripheral deformation with respect to ... Relatively early studies focused on the low-permeability nature of clay-rich fault ... contain large lenses of high-permeability fractured ('damage zone') host rock. Study of Shock Landslide-Type Geomechanical Model Test for ... link.springer.com/content/pdf/10.1007%2F978-3-642-31310-3_2.pdf of consequent rock slope under earthquake effect, and carried out the simulation testing study ... fracture evolution process, deformation and fracture evolutionary process and vibra- .... Picture 1 Model of block structure of bonding by the clay. [PDF]Deformation in cemented mudrock (Callovo–Oxfordian Clay) by ... www.solid-earth.net/8/291/2017/se-8-291-2017.pdf Mar 9, 2017 - deformed material, resealing the initial fracture porosity. 1 Introduction ... mental high-strain fault rocks have been studied extensively. (Bos and .... to predict the mechanical evolution of COX over the period of thousands of ...
