{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/99375"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/99375","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Numerical Analysis of RAP Elements under Dynamic Loading","abstract":"The 2010-2011 Canterbury, New Zealand, Earthquake Sequence (CES) resulted in 185 fatalities and approximately $NZ40 billion in damage, much of which was due to liquefaction and related phenomena. As a result, an extensive soil improvement field testing program was initiated and Rammed Aggregate Piers� (RAP) were shown to be a feasible method to mitigate the risk from liquefaction during future events. To better design and more fully assess the efficacy of reinforcement techniques against liquefaction, pre- and post-treatment in-situ test data are compiled, to include results from cone penetration tests (CPT), direct-push crosshole tests, and vibroseis (T-Rex) shaking tests. The data are used to evaluate the capabilities of numerical tools to predict the liquefaction response of unimproved and improved sites. A finite difference (FD) numerical model is developed in a FLAC platform and a coupled analysis using the Finn model with Byrne (1991) formulation is conducted. The FD model calibrated for top-down shakings similar to the vibroseis tests succeeded in qualitatively reproducing the general observed behavior without quantitatively matching the in-situ values for shear strains and excess pore pressure ratios. The introduction of the RAP elements to the FD model reduced the shear strain, but slightly overestimated that reduction. Considering more advanced constitutive models that better simulate the complexity of the soil behavior under dynamic loading would likely increase the accuracy of the predicted response.","abstract_html":"The 2010-2011 Canterbury, New Zealand, Earthquake Sequence (CES) resulted in 185 fatalities and approximately $NZ40 billion in damage, much of which was due to liquefaction and related phenomena. As a result, an extensive soil improvement field testing program was initiated and Rammed Aggregate Piers� (RAP) were shown to be a feasible method to mitigate the risk from liquefaction during future events. To better design and more fully assess the efficacy of reinforcement techniques against liquefaction, pre- and post-treatment in-situ test data are compiled, to include results from cone penetration tests (CPT), direct-push crosshole tests, and vibroseis (T-Rex) shaking tests. The data are used to evaluate the capabilities of numerical tools to predict the liquefaction response of unimproved and improved sites. A finite difference (FD) numerical model is developed in a FLAC platform and a coupled analysis using the Finn model with Byrne (1991) formulation is conducted. The FD model calibrated for top-down shakings similar to the vibroseis tests succeeded in qualitatively reproducing the general observed behavior without quantitatively matching the in-situ values for shear strains and excess pore pressure ratios. The introduction of the RAP elements to the FD model reduced the shear strain, but slightly overestimated that reduction. Considering more advanced constitutive models that better simulate the complexity of the soil behavior under dynamic loading would likely increase the accuracy of the predicted response.","abstract_has_math":false,"creators":["Saade, Angela Charbel"],"institution":"Virginia Tech","degree_name":"MS","degree_level":"masters","degree_discipline":"Civil Engineering","degree_department":"Civil and Environmental Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Yerro Colom, Alba"],"committee_members":["Green, Russell A.","Castellanos, Bernardo Antonio"],"year":2019,"date_issued":"2019-01-24","date_published":"2019-01-24","updated_at":"2026-07-22T22:19:09Z","subjects":["Liquefaction","Numerical Model","Dynamic Loading","Rammed Aggregate Pier®","Christchurch"],"languages":[],"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:18395"],"render_values":[{"text":"vt_gsexam:18395","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/99375","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Yerro Colom, Alba"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Green, Russell A.","Castellanos, Bernardo Antonio"]},{"key":"dc:contributor.department","label":"Department","values":["Civil and Environmental Engineering"]},{"key":"dc:creator","label":"Author","values":["Saade, Angela Charbel"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2020-07-18T06:00:24Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2020-07-18T06:00:24Z"]},{"key":"dc:date.issued","label":"Date","values":["2019-01-24"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Civil Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["MS"]},{"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":["Liquefaction","Numerical Model","Dynamic Loading","Rammed Aggregate Pier®","Christchurch"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"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:18395"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/99375"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The 2010-2011 Canterbury, New Zealand, Earthquake Sequence (CES) resulted in 185 fatalities and approximately $NZ40 billion in damage, much of which was due to liquefaction and related phenomena. As a result, an extensive soil improvement field testing program was initiated and Rammed Aggregate Piers� (RAP) were shown to be a feasible method to mitigate the risk from liquefaction during future events. To better design and more fully assess the efficacy of reinforcement techniques against liquefaction, pre- and post-treatment in-situ test data are compiled, to include results from cone penetration tests (CPT), direct-push crosshole tests, and vibroseis (T-Rex) shaking tests. The data are used to evaluate the capabilities of numerical tools to predict the liquefaction response of unimproved and improved sites. A finite difference (FD) numerical model is developed in a FLAC platform and a coupled analysis using the Finn model with Byrne (1991) formulation is conducted. The FD model calibrated for top-down shakings similar to the vibroseis tests succeeded in qualitatively reproducing the general observed behavior without quantitatively matching the in-situ values for shear strains and excess pore pressure ratios. The introduction of the RAP elements to the FD model reduced the shear strain, but slightly overestimated that reduction. Considering more advanced constitutive models that better simulate the complexity of the soil behavior under dynamic loading would likely increase the accuracy of the predicted response."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["During earthquakes, a significant loss of strength in soil can occur. This phenomenon, known as liquefaction, can have a devastating impact on the area affected. The 2010-2011 Canterbury, New Zealand, Earthquake Sequence (CES) resulted in 185 fatalities and approximately $NZ40 billion in damage, much of which was due to liquefaction and related phenomena. Consequently, the New Zealand Earthquake Commission implemented a field testing program in order to investigate the efficiency of ground improvement techniques in reducing soil liquefaction potential. One of the tested techniques was Rammed Aggregate Piers™ (RAP) and was shown to be a feasible method in mitigating the risk from liquefaction during future events. The focus of this study is to develop a numerical model capable of predicting the liquefaction response of unimproved and RAP-improved sites. Pre- and post-treatment test data are therefore compiled and used to calibrate the model. The numerical model calibrated for shakings similar to the on-site tests succeeded in qualitatively, but not quantitatively, reproducing the behavior observed in the field. The introduction of the RAP elements to the model revealed an improvement against liquefaction hazard; however, the improvement was overestimated compared to the field results. Considering more advanced numerical features that better simulate the complexity of the soil behavior under dynamic loading would likely increase the accuracy of the predicted response."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["MS"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Numerical Analysis of RAP Elements under Dynamic Loading"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Yerro Colom, Alba"],"dc:contributor.committeemember":["Green, Russell A.","Castellanos, Bernardo Antonio"],"dc:contributor.department":["Civil and Environmental Engineering"],"dc:creator":["Saade, Angela Charbel"],"dc:date.accessioned":["2020-07-18T06:00:24Z"],"dc:date.available":["2020-07-18T06:00:24Z"],"dc:date.issued":["2019-01-24"],"dc:description.abstract":["The 2010-2011 Canterbury, New Zealand, Earthquake Sequence (CES) resulted in 185 fatalities and approximately $NZ40 billion in damage, much of which was due to liquefaction and related phenomena. As a result, an extensive soil improvement field testing program was initiated and Rammed Aggregate Piers� (RAP) were shown to be a feasible method to mitigate the risk from liquefaction during future events. To better design and more fully assess the efficacy of reinforcement techniques against liquefaction, pre- and post-treatment in-situ test data are compiled, to include results from cone penetration tests (CPT), direct-push crosshole tests, and vibroseis (T-Rex) shaking tests. The data are used to evaluate the capabilities of numerical tools to predict the liquefaction response of unimproved and improved sites. A finite difference (FD) numerical model is developed in a FLAC platform and a coupled analysis using the Finn model with Byrne (1991) formulation is conducted. The FD model calibrated for top-down shakings similar to the vibroseis tests succeeded in qualitatively reproducing the general observed behavior without quantitatively matching the in-situ values for shear strains and excess pore pressure ratios. The introduction of the RAP elements to the FD model reduced the shear strain, but slightly overestimated that reduction. Considering more advanced constitutive models that better simulate the complexity of the soil behavior under dynamic loading would likely increase the accuracy of the predicted response."],"dc:description.abstractgeneral":["During earthquakes, a significant loss of strength in soil can occur. This phenomenon, known as liquefaction, can have a devastating impact on the area affected. The 2010-2011 Canterbury, New Zealand, Earthquake Sequence (CES) resulted in 185 fatalities and approximately $NZ40 billion in damage, much of which was due to liquefaction and related phenomena. Consequently, the New Zealand Earthquake Commission implemented a field testing program in order to investigate the efficiency of ground improvement techniques in reducing soil liquefaction potential. One of the tested techniques was Rammed Aggregate Piers™ (RAP) and was shown to be a feasible method in mitigating the risk from liquefaction during future events. The focus of this study is to develop a numerical model capable of predicting the liquefaction response of unimproved and RAP-improved sites. Pre- and post-treatment test data are therefore compiled and used to calibrate the model. The numerical model calibrated for shakings similar to the on-site tests succeeded in qualitatively, but not quantitatively, reproducing the behavior observed in the field. The introduction of the RAP elements to the model revealed an improvement against liquefaction hazard; however, the improvement was overestimated compared to the field results. Considering more advanced numerical features that better simulate the complexity of the soil behavior under dynamic loading would likely increase the accuracy of the predicted response."],"dc:description.degree":["MS"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:18395"],"dc:identifier.uri":["http://hdl.handle.net/10919/99375"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Liquefaction","Numerical Model","Dynamic Loading","Rammed Aggregate Pier®","Christchurch"],"dc:title":["Numerical Analysis of RAP Elements under Dynamic Loading"],"dc:type":["Thesis"],"thesis:degree_discipline":["Civil Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["MS"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:09Z"}