Numerical Analysis of Strain Localization in Rocks with Thermo-hydro-mechanical Couplings Using Cosserat Continuum

TitleNumerical Analysis of Strain Localization in Rocks with Thermo-hydro-mechanical Couplings Using Cosserat Continuum
Publication TypeJournal Article
Year of Publication2018
AuthorsH Rattez, I Stefanou, J Sulem, M Veveakis, and T Poulet
JournalRock Mechanics and Rock Engineering
Volume51
Issue10
Start Page3295
Pagination3295 - 3311
Date Published10/2018
Abstract

© 2018, Springer-Verlag GmbH Austria, part of Springer Nature. A numerical model for thermo-hydro-mechanical strong couplings in an elasto-plastic Cosserat continuum is developed to explore the influence of frictional heating and thermal pore fluid pressurization on the strain localization phenomenon. This model allows specifically to study the complete stress–strain response of a rock specimen, as well as the size of the strain localization zone for a rock taking into account its microstructure. The numerical implementation in a finite element code is presented, matching adequately analytical solutions or results from other simulations found in the literature. Two different applications of the numerical model are also presented to highlight its capabilities. The first one is a biaxial test on a saturated weak sandstone, for which the influence on the stress–strain response of the characteristic size of the microstructure and of thermal pressurization is investigated. The second one is the rapid shearing of a mature fault zone in the brittle part of the lithosphere. In this example, the evolution of the thickness of the localized zone and the influence of the permeability change on the stress–strain response are studied.

DOI10.1007/s00603-018-1529-7
Short TitleRock Mechanics and Rock Engineering