{"689551":{"#nid":"689551","#data":{"type":"event","title":"PhD Defense by Srinivas Vivek Bokkisa","body":[{"value":"\u003Cp\u003ESchool of Civil and Environmental Engineering\u003C\/p\u003E\u003Cp\u003EPh.D. Thesis Defense Announcement\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EMULTISCALE ASSESSMENT OF FABRIC IN GRANULAR SOILS\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EBy\u003Cstrong\u003E\u0026nbsp;Srinivas Vivek Bokkisa\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EAdvisor:\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EDr. Jorge Macedo\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003ECommittee Members:\u003Cstrong\u003E\u0026nbsp; Dr. David Frost (CEE\/GT), Dr. Sheng Dai (CEE\/GT), Dr. Pedro Arduino (CEE\/Univ. of Washington), Dr. Alba Yerro-Colom (CEE\/Virginia Tech), Dr. Alexandros Petalas (Offshore Geotechnics\/Durham University)\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EDate and Time:\u003Cstrong\u003E\u0026nbsp; April, 21, 2026.\u0026nbsp; 11 AM (ET)\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003ELocation:\u0026nbsp;SEB122 or \u003Ca href=\u0022https:\/\/nam12.safelinks.protection.outlook.com\/?url=https%3A%2F%2Fgatech.zoom.us%2Fj%2F92868470813\u0026amp;data=05%7C02%7Ctm186%40gtvault.onmicrosoft.com%7C327e7f94e5b24ce0734c08de94c01d5f%7C482198bbae7b4b258b7a6d7f32faa083%7C1%7C0%7C639111750030077653%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C\u0026amp;sdata=tGQjXBdgexH2LVuX7WiXLvOQ0vcZfyqVT6TDn2mdRd0%3D\u0026amp;reserved=0\u0022\u003Ehttps:\/\/gatech.zoom.us\/j\/92868470813\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003EABSTRACT\u003Cbr\u003ESoil fabric, the internal organization of particles, contacts, and voids, is a fundamental\u003Cbr\u003Evariable governing the mechanical behavior of granular soils. Within the framework of\u003Cbr\u003EAnisotropic Critical State Theory (ACST), this thesis investigates the role of soil fabric\u003Cbr\u003Eacross constitutive and macro scales, while also examining the microstructural basis of its\u003Cbr\u003Econstitutive representation. At the constitutive scale, the results show that the onset of\u003Cbr\u003Einstability is a directional and fabric-sensitive phenomenon governed by loading path, fabric\u003Cbr\u003Eanisotropy, and state. Under generalized loading, these interactions give rise to fabricdependent\u003Cbr\u003Einstability surfaces that distinguish stable from unstable states. The analyses\u003Cbr\u003Efurther show that the influence of initial anisotropic consolidation on instability depends on\u003Cbr\u003Ethe coupled effects of material compressibility, stress path, and fabric evolution. To support\u003Cbr\u003Ethe reliable engineering application of ACST-based modeling, robust stress-integration\u003Cbr\u003Estrategies are also developed and evaluated. At the macro scale, Material Point Method\u003Cbr\u003Esimulations show that cone penetration response is strongly fabric-sensitive, with different\u003Cbr\u003Einitial fabric orientations producing markedly different cone resistances even in soils with similar initial state. At the microstructural scale, X-ray micro-computed tomography and\u003Cbr\u003Eimage-based characterization of a clean sand prepared by different deposition methods show\u003Cbr\u003Ethat deposition history leaves a clear and measurable signature on inherent fabric, even at\u003Cbr\u003Esimilar global void ratio. The results further show that the measured fabric depends on both\u003Cbr\u003Epreparation method and the microstructural descriptor used to characterize it. Although the\u003Cbr\u003Emagnitude of anisotropy varies among descriptors, the dominant initial fabric direction\u003Cbr\u003Eremains predominantly horizontal, providing an experimental basis for interpreting initial\u003Cbr\u003Efabric tensors in ACST-based models. Overall, the thesis identifies soil fabric as a key\u003Cbr\u003Emultiscale variable governing granular soil behavior and provides new insights for its\u003Cbr\u003Einterpretation and modeling in geotechnical engineering.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003E\u003Cstrong\u003EMULTISCALE ASSESSMENT OF FABRIC IN GRANULAR SOILS\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"MULTISCALE ASSESSMENT OF FABRIC IN GRANULAR SOILS"}],"uid":"27707","created_gmt":"2026-04-07 20:53:46","changed_gmt":"2026-04-07 20:54:01","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2026-04-21T11:00:00-04:00","event_time_end":"2026-04-21T13:00:00-04:00","event_time_end_last":"2026-04-21T13:00:00-04:00","gmt_time_start":"2026-04-21 15:00:00","gmt_time_end":"2026-04-21 17:00:00","gmt_time_end_last":"2026-04-21 17:00:00","rrule":null,"timezone":"America\/New_York"},"location":"SEB122 ","extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}