{"id":10,"date":"2017-03-21T22:44:00","date_gmt":"2017-03-21T21:44:00","guid":{"rendered":"http:\/\/www.lmgc.univ-montp2.fr\/perso\/jolanta-lewandowska\/?page_id=10"},"modified":"2019-02-22T14:35:05","modified_gmt":"2019-02-22T13:35:05","slug":"recherche","status":"publish","type":"page","link":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/jolanta-lewandowska\/recherche\/","title":{"rendered":"Recherche"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\"><strong>POROMECHANICS <\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><em>(selected contributions)<\/em><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Lewandowska, J., Auriault, J.-L.,\n2013, Extension of Biot theory to the problem of saturated microporous elastic\nmedia with isolated cracks or\/and vugs. <\/strong><strong>Int. J. Numer. Anal. Meth. Geomech. Vol. 37, Issue 16, pages 2611-2628,\n<\/strong><strong>DOI&nbsp;:\n10.1002\/nag. 2150<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">By applying the asymptotic expansion\nhomogenization method, we develop the macroscopic model of hydro-mechanical\ncoupling for the case of a saturated porous medium containing isolated cracks\nor\/and vugs. The model represents an extension of the phenomenological Biot\nmodel that was initially formulated for a macroscopically homogeneous and\nisotropic elastic saturated porous medium. The homogenization analyse shows the\ngeneral structure of the Biot\u2019s model is preserved but the Biot\u2019s parameters\nare modified. In particular, the poro-elasticity parameters of the porous\nmatrix itself, as well as the volumetric fraction of the cracks (vugs), are\ntaken into account.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Two numerical examples of the computations of Biot\u2019s parameters in both isotropic and anisotropic cases, are presented. \u00a0It is also shown how the presence of near-zero-volume cracks influences the Biot\u2019s parameters of the cracked porous medium which can, in turn, significantly affect the overall behaviour of the porous medium through the hydro-mechanical coupling mechanism. In order to illustrate the practical importance and impact of the presence of cracks\/vugs, a macroscopic boundary value problem of water pumping from a porous aquifer is solved numerically for non-damaged and damaged cases.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Lewandowska, J., 2013,\nModelling by homogenization of the long term rock dissolution and geomechanical\neffects. (Chapitre VIII <em>dans<\/em> l\u2019ouvrage&nbsp; \u2018Geomechanics in CO2 storage facilities\u2019. Eds.\nG. Pijaudier-Cabot, J.M. Pereira. ISTE-Wiley, 21 pages, DOI:&nbsp;10.1002\/9781118577424.ch8<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The formulation of the macroscopic model\ndescribing the behaviour of a porous saturated rock subjected to the injection\nof CO<sub>2,<\/sub> is presented. The analysis is focused on the long term\neffects when the chemical reactions between the CO<sub>2<\/sub> dissolved in the\npore water and the solid matrix result in the dissolution (and \/or\nprecipitation) of the rock minerals.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The theoretical framework of the modelling is\nthe asymptotic developments homogenization method. At the microscopic scale,\ni.e. the scale of the microstructure, the following phenomena are taken into\naccount: i) water flow through the pores, ii) linear elasticity of the solid\nphase, iii) mass transport of dissolved CO<sub>2 <\/sub>in water phase, iv)\nchemical dissolution of the solid matrix. After homogenization process, the full\nmacroscopic model of coupled phenomena is obtained. One of the contributions of the paper is the formulation of the local\nchemical degradation mechanism. It is assumed that the dissolution process\nis governed by a diffusion-like equation for the concentration in solid (solid\nfraction), with a single parameter (in tensorial form) describing the rate of\nthe process.&nbsp; Such a formulation enables\nus to capture the chemo-mechanical coupling manifesting itself at the\nmacroscopic scale. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This general mathematical framework was\nillustrated by an example of numerical computations of\nthe degradation with time of mechanical parameters of the rock in case of a three\ndimensional microstructure showing cubic symmetry at the macroscopic scale. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Wojtacki, K., Lewandowska, J.,\nGouze, Ph.,&nbsp; Lipkowski, A.,&nbsp; 2015, <\/strong><strong>Numerical computation\nof rock dissolution and geomechanical effects for CO2 geological storage. <\/strong><strong>International Journal of Numerical and Analytical Methods in\nGeomechanics, Volume 39, Issue 5, pp. 482-506, DOI: 10.1002\/nag.2316<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We present a methodology for the assessment of\nthe impact of progressive rock dissolution on the mechanical behaviour of a\nporous rock. The method is based on the use of the X-ray tomography and the\nnumerical dissolution technique of the rock sample. The influence of the\nevolution of the microstructure on the macroscopic properties of the rock is\nanalysed by using the periodic homogenization method. The numerical\ncomputations show progressive degradation of all components of the stiffness\ntensor (orthotropic case). Moreover, the evolution of the associated mass\ntransfer properties (conductivity tensor, tortuosity tensor and specific\nsurface) is also calculated by using the same homogenization approach. The\ncorrelation analyse shows that the highest increase in the hydraulic\nconductivity is not associated with the highest decrease of the Young modulus\nin the same direction. Further, the highest decrease of the Young modulus is\nnot associated with the appearance of percolation in this direction. The\nobtained results clearly show the importance of morphological information about\nthe microstructure as a key to the understanding of the coupled multi-physics phenomena.\n<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Finally, an incremental law for a problem of deep aquifer settlement due to the rock dissolution under constant stress and drained conditions, is proposed. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><br><br><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>POROMECHANICS (selected contributions) Lewandowska, J., Auriault, J.-L., 2013, Extension of Biot theory to the problem of saturated microporous elastic media with isolated cracks or\/and vugs. Int. J. Numer. Anal. Meth. Geomech. Vol. 37, Issue 16, pages 2611-2628, DOI&nbsp;: 10.1002\/nag. 2150 By applying the asymptotic expansion homogenization method, we develop the macroscopic model of hydro-mechanical coupling&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-10","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/jolanta-lewandowska\/wp-json\/wp\/v2\/pages\/10","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/jolanta-lewandowska\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/jolanta-lewandowska\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/jolanta-lewandowska\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/jolanta-lewandowska\/wp-json\/wp\/v2\/comments?post=10"}],"version-history":[{"count":12,"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/jolanta-lewandowska\/wp-json\/wp\/v2\/pages\/10\/revisions"}],"predecessor-version":[{"id":111,"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/jolanta-lewandowska\/wp-json\/wp\/v2\/pages\/10\/revisions\/111"}],"wp:attachment":[{"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/jolanta-lewandowska\/wp-json\/wp\/v2\/media?parent=10"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}