Effect of decompression and suction on macroscopic and microscopic behavior of a clay rock

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• 作者：Xin Wei ; Myriam Duc ; Mahdia Hattab ; Thierry Reuschlé ; Said Taibi…
• 关键词：Claystone ; Cracking ; Decompression ; Drying–wetting path ; Suction
• 刊名：Acta Geotechnica
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：12
• 期：1
• 页码：47-65
• 全文大小：
• 刊物类别：Engineering
• 刊物主题：Geoengineering, Foundations, Hydraulics; Continuum Mechanics and Mechanics of Materials; Geotechnical Engineering & Applied Earth Sciences; Soil Science & Conservation; Soft and Granular Matter, Compl
• 出版者：Springer Berlin Heidelberg
• ISSN：1861-1133
• 卷排序：12

文摘

The goal in this research was to analyze the effects of decompression and suction on the formation of cracks in a clay rock from the Andra (French National Radioactive Waste Management Agency) site at Bure (Meuse–Haute-Marne, France). The article investigates the relationship between the changes in the hydromechanical properties and the changes in microstructure and porosity. Concerning the effect of decompression, at the macroscopic scale, the study highlighted an important effect on the elastic modulus and permeability, but little effect at the microscopic scale except an evolution of mineralogy related to the oxidation of pyrite often present in layers where cracks develop. Concerning the effect of suction, at the macroscopic level, the results showed that, on drying path, the change in the properties of the material was very small, whereas, on wetting path, a large decrease in tensile strength and gas permeability was observed. At the microscopic level, observations with SEM and ESEM, and measurements with MIP, highlighted the evolution of microstructural organization as a function of suction, and the propagation and enlargement of cracks on wetting path, rather than on drying path.