{"593112":{"#nid":"593112","#data":{"type":"event","title":"PhD Defense by Esmaeel Bakhtiary","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ESchool of Civil and Environmental Engineering\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EPh.D. Thesis Defense Announcement\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EAssessment of Guardrail Systems in Stiff Ground Layers via Continuum and Discrete Simulation Approaches\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EBy\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EEsmaeel Bakhtiary\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003E\u0026nbsp;\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EAdvisors:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Lauren K. Stewart\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ECommittee Members:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Donald W. White (CEE, Co-Advisor), Dr. David W. Scott (CEE), Dr. David Frost (CEE), Dr. Min Zhou (ME)\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EDate \u0026amp; Time:\u003C\/strong\u003E Thursday, July 19\u003Csup\u003Eth\u003C\/sup\u003E, 3:00pm\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ELocation:\u003C\/strong\u003E Mason Building Room 3132\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EAssessment of Guardrail Systems in Stiff Ground Layers via Continuum and Discrete Simulation Approaches\u003C\/p\u003E\r\n\r\n\u003Cp\u003EMow strips are asphalt or concrete layers, which are used as vegetation barriers around guardrail posts in the\u003C\/p\u003E\r\n\r\n\u003Cp\u003Edesign of roadside safety structures. Asphalt mow strips have historically been modeled as a rigid layer in\u003C\/p\u003E\r\n\r\n\u003Cp\u003Esimulations. This assumption often results in unrealistic ground level restraint of the guardrail post. Recent\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eexperiments conducted in a parallel research effort have shown that asphalt rupture and other material behavior\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eshould be considered in the analysis of the response of guardrail posts embedded in mow strips.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThis study provides an accurate and efficient approach for simulating the guardrail system and investigates the\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eeffect of asphalt material properties and mow strip geometry on the guardrail system performance. Simplified\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eanalytical solutions are constructed to obtain the lateral capacity of posts embedded in asphalt mow strips. These\u003C\/p\u003E\r\n\r\n\u003Cp\u003Esolutions are further enhanced by combining finite element simulations and regression analysis to provide predictive\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eequations for lateral strength and stiffness of asphalt mow strips. The predictive equations are utilized to construct\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eforce-displacement curves (p-y curves) for asphalt layers with various rear distances and material properties. The p-y\u003C\/p\u003E\r\n\r\n\u003Cp\u003Ecurves are employed to efficiently model asphalt mow strips using nonlinear uncoupled springs. Moreover, several\u003C\/p\u003E\r\n\r\n\u003Cp\u003Emow strip designs with various thicknesses, rear distances behind the posts, and asphalt pre-cuts are investigated to\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eprovide recommendations for retrofit techniques and new construction.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe recommended retrofit and new construction techniques are evaluated with static and dynamic numerical\u003C\/p\u003E\r\n\r\n\u003Cp\u003Esimulations of guardrail posts embedded in asphalt mow strips, and full-scale crash simulations of the guardrail\u003C\/p\u003E\r\n\r\n\u003Cp\u003Esystems are performed. The results are compared with available data from experiments and material tests. The\u003C\/p\u003E\r\n\r\n\u003Cp\u003Esimulation results for guardrail posts are used to evaluate the level of restraint provided by the asphalt mow strips.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThereafter, full-scale crash simulation results are evaluated using guidelines in the Manual for Assessing Safety\u003C\/p\u003E\r\n\r\n\u003Cp\u003EHardware (MASH).\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Assessment of Guardrail Systems in Stiff Ground Layers via Continuum and Discrete Simulation Approaches"}],"uid":"27707","created_gmt":"2017-06-29 14:30:20","changed_gmt":"2017-06-29 15:02:00","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2017-07-19T16:00:00-04:00","event_time_end":"2017-07-19T18:01:00-04:00","event_time_end_last":"2017-07-19T18:01:00-04:00","gmt_time_start":"2017-07-19 20:00:00","gmt_time_end":"2017-07-19 22:01:00","gmt_time_end_last":"2017-07-19 22:01:00","rrule":null,"timezone":"America\/New_York"},"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":"78761","name":"Faculty\/Staff"},{"id":"78771","name":"Public"},{"id":"78751","name":"Undergraduate students"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}