{"id":18039,"date":"2024-11-13T08:52:42","date_gmt":"2024-11-13T07:52:42","guid":{"rendered":"https:\/\/navier-lab.fr\/?p=18039"},"modified":"2024-11-13T09:06:02","modified_gmt":"2024-11-13T08:06:02","slug":"soutenance-de-these-catherine-dore-ossipyan","status":"publish","type":"post","link":"https:\/\/navier-lab.fr\/en\/soutenance-de-these-catherine-dore-ossipyan\/","title":{"rendered":"PhD Defense \u2013 Catherine Dor\u00e9-Ossipyan"},"content":{"rendered":"<section class=\"kc-elm kc-css-711642 kc_row\"><div class=\"kc-row-container  kc-container\"><div class=\"kc-wrap-columns\"><div class=\"kc-elm kc-css-526815 kc_col-sm-12 kc_column kc_col-sm-12\"><div class=\"kc-col-container\"><div class=\"kc-elm kc-css-442025 kc_text_block\"><\/p>\n<p>Catherine Dor\u00e9-Ossipyan, PhD student in the Geotechnics and Multiscale team, will defend her PhD thesis entitled <span lang=\"EN-GB\">\u201c<em>Multi-scale Analysis of a Porous Rock under Triaxial Loading<\/em>\u201d on <\/span><span lang=\"EN-GB\" data-olk-copy-source=\"MessageBody\">Tuesday the <sup>19th<\/sup> of November starting at 2pm in the Cauchy amphitheatre. <\/span><\/p>\n<p class=\"x_MsoNormal\"><span lang=\"EN-GB\" data-olk-copy-source=\"MessageBody\"><strong>Composition of the jury:<\/strong><br \/><\/span><\/p>\n<ul>\n<li class=\"x_MsoNoSpacing\">\n<p class=\"x_MsoNoSpacing\"><span lang=\"FR\" data-olk-copy-source=\"MessageBody\">Patrick Baud \u2013 Ecole et Observatoire des Sciences de la Terre \u2013 Reporter<\/span><\/p>\n<\/li>\n<li class=\"x_MsoNoSpacing\">\n<p class=\"x_MsoNoSpacing\"><span lang=\"FR\">J\u00e9r\u00f4me Fortin \u2013 Ecole Normale Sup\u00e9rieure \u2013 Reporter<\/span><\/p>\n<\/li>\n<li class=\"x_MsoNoSpacing\">\n<p class=\"x_MsoNoSpacing\">Elisabeth Bemer\u2013 IFPEN<span lang=\"FR\"> \u2013 <\/span>Examiner<\/p>\n<\/li>\n<li class=\"x_MsoNoSpacing\">\n<p class=\"x_MsoNoSpacing\">Alexis Cartwright-Taylor \u2013 Heriott-Watt University<span lang=\"FR\"> \u2013 <\/span>Examiner<\/p>\n<\/li>\n<li class=\"x_MsoNoSpacing\">\n<p class=\"x_MsoNoSpacing\"><span lang=\"FR\">Pierre B\u00e9suelle \u2013 Laboratoire 3SR \u2013 Examiner<\/span><\/p>\n<\/li>\n<li class=\"x_MsoNoSpacing\">\n<p class=\"x_MsoNoSpacing\"><span lang=\"FR\">Jean Sulem \u2013 \u00c9cole des Ponts \u2013 Director<\/span><\/p>\n<\/li>\n<li class=\"x_MsoNoSpacing\">\n<p class=\"x_MsoNoSpacing\"><span lang=\"FR\">Michel Bornert \u2013 \u00c9cole des Ponts \u2013 Co-supervisor<\/span><\/p>\n<\/li>\n<li class=\"x_MsoNoSpacing\">\n<p class=\"x_MsoNoSpacing\"><span lang=\"FR\">Alexandre Dimanov \u2013 IPP-X \u2013 Co-supervispr<\/span><\/p>\n<\/li>\n<\/ul>\n<p class=\"x_MsoNoSpacing\"><span lang=\"EN-GB\">\u00a0<\/span><\/p>\n<p>\n<\/div><div data-closeall=\"true\" class=\"kc-elm kc-css-551972 kc_accordion_wrapper\">\n    <h3 class=\"kc-accordion-title\">Abstract<\/h3>\n<div class=\"kc-elm kc-css-652204 kc_accordion_section group \"><h3 class=\"kc_accordion_header ui-accordion-header\"><span class=\"ui-accordion-header-icon ui-icon\"><\/span><a href=\"#show-the-abstract\" data-prevent=\"scroll\"><i class=\"\"><\/i> Show the abstract<\/a><\/h3><div class=\"kc_accordion_content ui-accordion-content kc_clearfix\"><div class=\"kc-panel-body\"><div class=\"kc-elm kc-css-813718 kc_text_block\"><\/p>\n<p style=\"text-align: justify;\">One of the solutions being considered for reducing emissions of greenhouse gases is their capture and geological sequestration. Porous carbonate rocks are considered excellent candidates due to their high capacity and permeability, but they are also inherently heterogeneous and multi-scale. Experimental and field studies carried out in the last two decades showed that, under multiaxial loading conditions, they accommodate deformation heterogeneously, which has an impact on porosity and its distribution, which in turn affects permeability. Carbonates present a very large microstructural variability when compared to sandstones, and a special attention has to be brought to the study of the link between microstructure and deformation modes.<\/p>\n<p style=\"text-align: justify;\">In the present work, deformation modes are studied experimentally on a high porosity carbonate rock (38% on average), the Saint-Maximin limestone. This rock presents dense and porous zones which alternate at centimeter scale. An earlier study on 40mm diameter samples showed that the nucleation and propagation of bands is controlled by porosity heterogeneity at the centimeter scale. To understand the role of microstructure on observed band patterns, samples of 8 mm in diameter were cored in both types of zones, and their deformation modes were investigated by combining imaging techniques on evolving material at various loading conditions. A total of twelve samples were tested using a new in situ triaxial device, and imaged continuously using fast and highly-resolved synchrotron tomography (Psich\u00e9 beamline, Soleil). 3D strain fields using Digital Volume Correlation, and porosity maps, both computed at the same gauge length are constructed. The entire strain and porosity evolutions for each subvolume is thus known. Global and local measures are analyzed to understand the scaling effects of microstructure on deformation modes. Both types of microstructures show brittle behavior at low confining pressure and ductile yielding at high confining pressure. Localized and diffuse deformation is shown to initiate in the most porous millimeter-sized zones. In addition, dense samples present a transitional behavior at intermediate confining pressures, linked to its heterogeneous microstructure. On the local scale, localized deformation is associated with homogenization around a critical value, where more porous zones compact, and denser zones dilate. Diffuse compaction at higher confining pressure acts as progressive densification until a homogeneous state is reached. Local yielding is shown to depend on initial porosity and post- yield behavior on the stress-path. This study provides a substantial amount of high-quality data on deformation modes in a heterogeneous porous carbonate rock, allowing to understand how local porosity controls global behavior at different scales and various loading conditions.<\/p>\n<p>\n<\/div><\/div><\/div><\/div><\/div>\n<\/div><\/div><\/div><\/div><\/section>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":158,"featured_media":18041,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[266,251,291,292,299],"tags":[],"class_list":["post-18039","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-actualites-en","category-annonces-en","category-annonces-geotech-en","category-annonces-me-en","category-soutenances-de-these-en"],"acf":[],"_links":{"self":[{"href":"https:\/\/navier-lab.fr\/en\/wp-json\/wp\/v2\/posts\/18039","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/navier-lab.fr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/navier-lab.fr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/navier-lab.fr\/en\/wp-json\/wp\/v2\/users\/158"}],"replies":[{"embeddable":true,"href":"https:\/\/navier-lab.fr\/en\/wp-json\/wp\/v2\/comments?post=18039"}],"version-history":[{"count":4,"href":"https:\/\/navier-lab.fr\/en\/wp-json\/wp\/v2\/posts\/18039\/revisions"}],"predecessor-version":[{"id":18060,"href":"https:\/\/navier-lab.fr\/en\/wp-json\/wp\/v2\/posts\/18039\/revisions\/18060"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/navier-lab.fr\/en\/wp-json\/wp\/v2\/media\/18041"}],"wp:attachment":[{"href":"https:\/\/navier-lab.fr\/en\/wp-json\/wp\/v2\/media?parent=18039"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/navier-lab.fr\/en\/wp-json\/wp\/v2\/categories?post=18039"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/navier-lab.fr\/en\/wp-json\/wp\/v2\/tags?post=18039"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}