{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/135539"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/135539","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Experimental and Analytical Investigation of Seismic Performance and Retrofit Techniques for Non-Ductile RC Structural Walls","abstract":"Reinforced concrete (RC) walls are widely used as lateral-force-resisting systems. Despite the interest in retrofitting techniques, critical knowledge gaps remain regarding the reliability and validity of current retrofit design guidelines and procedures, particularly for barbell walls with single sided retrofit strategies, and barbell walls with inadequate lap splices. This dissertation is aimed at addressing this need through a combination of experimental and numerical investigations focused on non-ductile RC structural walls. Six non-ductile barbell experimental specimens were built and designed with varying retrofit strategies including single sided fiber reinforced polymer (FRP) overlay, single sided RC overlay, end wrapped bar buckling and lap splice confinement. Brittle shear deformation was precluded in the web through shear strengthening strategies, while bar buckling and lap splice slip were effectively prevented through the current ACI-440 design equations. The end wrapping strategies also had the unintended consequence of localizing strains to the base of their respective specimens, which resulted in a large number of fractured rebar. The experimental results were compared to numerical models through the nonlinear truss analogy, which was adapted for this work to incorporate lap splice slip and overlay considerations. The experimental results were well estimated by this numerical modeling approach, achieving within 6% of the peak strength of all experimentally obtained values, as well as accurately predicting the failure modes. The nonlinear truss model is a computationally efficient and user-friendly implementation of a nonlinear finite element strategy. A parametric study was undertaken on a set of 200 rectangular and barbell walls to assess the sensitivity of several parameters typical in older (pre-1970s) structural walls, as well as to compare two assessment methodologies: a set of strain-based criteria and the current ASCE-41 guidelines. The results of the parametric study indicate a reasonable ability of the strain-based methodology to consistently capture key performance metrics of the backbone curve while maintaining a similar statistical spread and trend to the performance metrics obtained through the ASCE-41 guidelines for most cases of flexurally-controlled walls. This indicates that the strain-based failure criteria can be an equally effective method used to capture seismic behavior of older RC walls and may even be preferred as an alternative assessment procedure, since it relies on a local assessment framework which can be uniquely adapted for any structure or retrofit configuration.","abstract_html":"Reinforced concrete (RC) walls are widely used as lateral-force-resisting systems. Despite the interest in retrofitting techniques, critical knowledge gaps remain regarding the reliability and validity of current retrofit design guidelines and procedures, particularly for barbell walls with single sided retrofit strategies, and barbell walls with inadequate lap splices. This dissertation is aimed at addressing this need through a combination of experimental and numerical investigations focused on non-ductile RC structural walls. Six non-ductile barbell experimental specimens were built and designed with varying retrofit strategies including single sided fiber reinforced polymer (FRP) overlay, single sided RC overlay, end wrapped bar buckling and lap splice confinement. Brittle shear deformation was precluded in the web through shear strengthening strategies, while bar buckling and lap splice slip were effectively prevented through the current ACI-440 design equations. The end wrapping strategies also had the unintended consequence of localizing strains to the base of their respective specimens, which resulted in a large number of fractured rebar. The experimental results were compared to numerical models through the nonlinear truss analogy, which was adapted for this work to incorporate lap splice slip and overlay considerations. The experimental results were well estimated by this numerical modeling approach, achieving within 6% of the peak strength of all experimentally obtained values, as well as accurately predicting the failure modes. The nonlinear truss model is a computationally efficient and user-friendly implementation of a nonlinear finite element strategy. A parametric study was undertaken on a set of 200 rectangular and barbell walls to assess the sensitivity of several parameters typical in older (pre-1970s) structural walls, as well as to compare two assessment methodologies: a set of strain-based criteria and the current ASCE-41 guidelines. The results of the parametric study indicate a reasonable ability of the strain-based methodology to consistently capture key performance metrics of the backbone curve while maintaining a similar statistical spread and trend to the performance metrics obtained through the ASCE-41 guidelines for most cases of flexurally-controlled walls. This indicates that the strain-based failure criteria can be an equally effective method used to capture seismic behavior of older RC walls and may even be preferred as an alternative assessment procedure, since it relies on a local assessment framework which can be uniquely adapted for any structure or retrofit configuration.","abstract_has_math":false,"creators":["Albright, Jenifer Ann"],"institution":"Virginia Tech","degree_name":"Doctor of Philosophy","degree_level":"doctoral","degree_discipline":"Civil Engineering","degree_department":"Civil and Environmental Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Koutromanos, Ioannis"],"committee_members":["Murcia-Delso, Juan","Eatherton, Matthew Roy","Jacques, Eric Jean-Yves"],"year":2025,"date_issued":"2025-06-18","date_published":"2025-06-18","updated_at":"2026-07-22T22:18:41Z","subjects":["Structural Shear Walls","Seismic Assessment","Retrofit","Lap-splice","Analytical Modeling"],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:43536"],"render_values":[{"text":"vt_gsexam:43536","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10919/135539","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Koutromanos, Ioannis"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Murcia-Delso, Juan","Eatherton, Matthew Roy","Jacques, Eric Jean-Yves"]},{"key":"dc:contributor.department","label":"Department","values":["Civil and Environmental Engineering"]},{"key":"dc:creator","label":"Author","values":["Albright, Jenifer Ann"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2025-06-19T08:00:53Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2025-06-19T08:00:53Z"]},{"key":"dc:date.issued","label":"Date","values":["2025-06-18"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Civil Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Structural Shear Walls","Seismic Assessment","Retrofit","Lap-splice","Analytical Modeling"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:43536"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10919/135539"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Reinforced concrete (RC) walls are widely used as lateral-force-resisting systems. Despite the interest in retrofitting techniques, critical knowledge gaps remain regarding the reliability and validity of current retrofit design guidelines and procedures, particularly for barbell walls with single sided retrofit strategies, and barbell walls with inadequate lap splices. This dissertation is aimed at addressing this need through a combination of experimental and numerical investigations focused on non-ductile RC structural walls. Six non-ductile barbell experimental specimens were built and designed with varying retrofit strategies including single sided fiber reinforced polymer (FRP) overlay, single sided RC overlay, end wrapped bar buckling and lap splice confinement. Brittle shear deformation was precluded in the web through shear strengthening strategies, while bar buckling and lap splice slip were effectively prevented through the current ACI-440 design equations. The end wrapping strategies also had the unintended consequence of localizing strains to the base of their respective specimens, which resulted in a large number of fractured rebar. The experimental results were compared to numerical models through the nonlinear truss analogy, which was adapted for this work to incorporate lap splice slip and overlay considerations. The experimental results were well estimated by this numerical modeling approach, achieving within 6% of the peak strength of all experimentally obtained values, as well as accurately predicting the failure modes. The nonlinear truss model is a computationally efficient and user-friendly implementation of a nonlinear finite element strategy. A parametric study was undertaken on a set of 200 rectangular and barbell walls to assess the sensitivity of several parameters typical in older (pre-1970s) structural walls, as well as to compare two assessment methodologies: a set of strain-based criteria and the current ASCE-41 guidelines. The results of the parametric study indicate a reasonable ability of the strain-based methodology to consistently capture key performance metrics of the backbone curve while maintaining a similar statistical spread and trend to the performance metrics obtained through the ASCE-41 guidelines for most cases of flexurally-controlled walls. This indicates that the strain-based failure criteria can be an equally effective method used to capture seismic behavior of older RC walls and may even be preferred as an alternative assessment procedure, since it relies on a local assessment framework which can be uniquely adapted for any structure or retrofit configuration."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["Reinforced concrete buildings are incredibly common structures around the world. They are also often found in historically active earthquake regions. It is imperative that these structures are strong enough and flexible enough to withstand large earthquakes without collapsing or having rapid collapses. Structures designed pre-1970s in the US are at an inherent deficit for adequate response during earthquake events due to their lack of sufficient steel in critical regions to maximize their deformability. Therefore, to increase the capacity and the safety of these structures this dissertation explored the retrofitting techniques of concrete overlay and fiber reinforced polymer wrap. Both of these techniques were found to be effective in strengthening the specimens and improving their ductile response during loading. Furthermore, numerical models were developed to gain a broad understanding of typical older wall structures and their failure patterns."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Doctor of Philosophy"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Experimental and Analytical Investigation of Seismic Performance and Retrofit Techniques for Non-Ductile RC Structural Walls"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Koutromanos, Ioannis"],"dc:contributor.committeemember":["Murcia-Delso, Juan","Eatherton, Matthew Roy","Jacques, Eric Jean-Yves"],"dc:contributor.department":["Civil and Environmental Engineering"],"dc:creator":["Albright, Jenifer Ann"],"dc:date.accessioned":["2025-06-19T08:00:53Z"],"dc:date.available":["2025-06-19T08:00:53Z"],"dc:date.issued":["2025-06-18"],"dc:description.abstract":["Reinforced concrete (RC) walls are widely used as lateral-force-resisting systems. Despite the interest in retrofitting techniques, critical knowledge gaps remain regarding the reliability and validity of current retrofit design guidelines and procedures, particularly for barbell walls with single sided retrofit strategies, and barbell walls with inadequate lap splices. This dissertation is aimed at addressing this need through a combination of experimental and numerical investigations focused on non-ductile RC structural walls. Six non-ductile barbell experimental specimens were built and designed with varying retrofit strategies including single sided fiber reinforced polymer (FRP) overlay, single sided RC overlay, end wrapped bar buckling and lap splice confinement. Brittle shear deformation was precluded in the web through shear strengthening strategies, while bar buckling and lap splice slip were effectively prevented through the current ACI-440 design equations. The end wrapping strategies also had the unintended consequence of localizing strains to the base of their respective specimens, which resulted in a large number of fractured rebar. The experimental results were compared to numerical models through the nonlinear truss analogy, which was adapted for this work to incorporate lap splice slip and overlay considerations. The experimental results were well estimated by this numerical modeling approach, achieving within 6% of the peak strength of all experimentally obtained values, as well as accurately predicting the failure modes. The nonlinear truss model is a computationally efficient and user-friendly implementation of a nonlinear finite element strategy. A parametric study was undertaken on a set of 200 rectangular and barbell walls to assess the sensitivity of several parameters typical in older (pre-1970s) structural walls, as well as to compare two assessment methodologies: a set of strain-based criteria and the current ASCE-41 guidelines. The results of the parametric study indicate a reasonable ability of the strain-based methodology to consistently capture key performance metrics of the backbone curve while maintaining a similar statistical spread and trend to the performance metrics obtained through the ASCE-41 guidelines for most cases of flexurally-controlled walls. This indicates that the strain-based failure criteria can be an equally effective method used to capture seismic behavior of older RC walls and may even be preferred as an alternative assessment procedure, since it relies on a local assessment framework which can be uniquely adapted for any structure or retrofit configuration."],"dc:description.abstractgeneral":["Reinforced concrete buildings are incredibly common structures around the world. They are also often found in historically active earthquake regions. It is imperative that these structures are strong enough and flexible enough to withstand large earthquakes without collapsing or having rapid collapses. Structures designed pre-1970s in the US are at an inherent deficit for adequate response during earthquake events due to their lack of sufficient steel in critical regions to maximize their deformability. Therefore, to increase the capacity and the safety of these structures this dissertation explored the retrofitting techniques of concrete overlay and fiber reinforced polymer wrap. Both of these techniques were found to be effective in strengthening the specimens and improving their ductile response during loading. Furthermore, numerical models were developed to gain a broad understanding of typical older wall structures and their failure patterns."],"dc:description.degree":["Doctor of Philosophy"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:43536"],"dc:identifier.uri":["https://hdl.handle.net/10919/135539"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Structural Shear Walls","Seismic Assessment","Retrofit","Lap-splice","Analytical Modeling"],"dc:title":["Experimental and Analytical Investigation of Seismic Performance and Retrofit Techniques for Non-Ductile RC Structural Walls"],"dc:type":["Dissertation"],"thesis:degree_discipline":["Civil Engineering"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Doctor of Philosophy"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:18:41Z"}