Hydro-Mechanical Coupling and Failure Behavior of Argillaceous Sedimentary Rocks: A Multi-Scale Approach
Date
2019-04-26
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Abstract
This thesis aims at characterizing the hydro-mechanical behavior of argillaceous sedimentary rocks within a novel poro-elasto-plasticity framework that encompasses micro-mechanics and a multi-scale approach. The developed model considers argillaceous sedimentary rocks to be comprised of a mixture of clay aggregates and rock-type inclusions. The clay fraction has a dual porosity arising from micropores at the clay aggregate level and nanopores between the clay platelets that form the clay aggregates. The rock-type inclusions also have a dual porosity due to the presence of microcracks embedded into a nano-porous rock matrix. As such, the work develops multi-scale modeling techniques that elucidate the complex macroscopic characteristics observed in clay-rich rocks by advocating only the primitive physical laws at their fundamental scales. The outcome is an analytical constitutive law that transcends the various scales: from nano- to macro-scale. Therefore, the swelling stress originating in the nano-pores of clay particles and capillary stresses in the porous network, as well as micro-crack growth can be readily computed as a function of microstructure and physics across the various scales. The developed model is implemented within numerical modeling frameworks such as Finite Element Method (FEM) and eXtended FEM. Lab experimentally observed phenomena in argillaceous sedimentary rocks such as plastic/swelling deformations of clay aggregates and the failure of rock inclusions through micro-crack growth are successfully replicated.
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Micromechanics, Clay-rock, Failure, Homogenization, Multiscale, Partial saturation, Swelling, Fracture, Extended Finite Element Method, Microcrack
Citation
Eghbalian, M. (2019). Hydro-mechanical coupling and failure behavior of argillaceous sedimentary rocks: A multi-scale approach (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.