{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/29048"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/29048","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Micromechanical Aspects of Aging in Granular Soils","abstract":"Granular soils exhibit a generally beneficial change in engineering properties with time after deposition or densification, during a process commonly known as aging. Soil properties reported to change during aging include the small strain modulus and stiffness, penetration resistance, liquefaction resistance, and pile setup. Different hypotheses have been proposed to explain the occurrence of aging in granular soils, including cementation induced by dissolution of silica and precipitation at the particle contacts, cementation due to microbiological activity, internal stress redistribution caused by particle crushing, and buckling of the load chains due to particle slippage. New evidence points out that internal and time-dependent changes in the soil structure caused by particle slippage and rearrangement as the source of the time-dependent variations in soil properties. This investigation is focused on the study of aging at the particle scale to determine its main driving mechanism and define the factors which affect it. Results from an extensive laboratory testing program and computer simulations based on the discrete element method provide insight into the causes of aging and its effects on the macroscopic properties of sands based on the analysis of the interaction between sand grains.","abstract_html":"Granular soils exhibit a generally beneficial change in engineering properties with time after deposition or densification, during a process commonly known as aging. Soil properties reported to change during aging include the small strain modulus and stiffness, penetration resistance, liquefaction resistance, and pile setup. Different hypotheses have been proposed to explain the occurrence of aging in granular soils, including cementation induced by dissolution of silica and precipitation at the particle contacts, cementation due to microbiological activity, internal stress redistribution caused by particle crushing, and buckling of the load chains due to particle slippage. New evidence points out that internal and time-dependent changes in the soil structure caused by particle slippage and rearrangement as the source of the time-dependent variations in soil properties. This investigation is focused on the study of aging at the particle scale to determine its main driving mechanism and define the factors which affect it. Results from an extensive laboratory testing program and computer simulations based on the discrete element method provide insight into the causes of aging and its effects on the macroscopic properties of sands based on the analysis of the interaction between sand grains.","abstract_has_math":false,"creators":["Suarez Zambrano, Nestor Ricardo"],"institution":"Virginia Tech","degree_name":"Ph. D.","degree_level":"doctoral","degree_discipline":"Civil Engineering","degree_department":"Civil Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Brandon, Thomas L.","Mitchell, James K."],"committee_members":["Green, Russell A.","Filz, George M."],"year":2012,"date_issued":"2012-09-03","date_published":"2012-09-03","updated_at":"2026-07-22T22:19:26Z","subjects":["Aging","creep","sand","acoustic emissions","computed tomography","discrete element method","rate process theory"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-09212012-220649"],"render_values":[{"text":"etd-09212012-220649","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/29048","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Brandon, Thomas L.","Mitchell, James K."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Green, Russell A.","Filz, George M."]},{"key":"dc:contributor.department","label":"Department","values":["Civil Engineering"]},{"key":"dc:creator","label":"Author","values":["Suarez Zambrano, Nestor Ricardo"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:16:31Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:16:31Z","2012-11-09"]},{"key":"dc:date.issued","label":"Date","values":["2012-09-03"]},{"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":["Ph. 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Soil properties reported to change during aging include the small strain modulus and stiffness, penetration resistance, liquefaction resistance, and pile setup. Different hypotheses have been proposed to explain the occurrence of aging in granular soils, including cementation induced by dissolution of silica and precipitation at the particle contacts, cementation due to microbiological activity, internal stress redistribution caused by particle crushing, and buckling of the load chains due to particle slippage. New evidence points out that internal and time-dependent changes in the soil structure caused by particle slippage and rearrangement as the source of the time-dependent variations in soil properties. This investigation is focused on the study of aging at the particle scale to determine its main driving mechanism and define the factors which affect it. Results from an extensive laboratory testing program and computer simulations based on the discrete element method provide insight into the causes of aging and its effects on the macroscopic properties of sands based on the analysis of the interaction between sand grains."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph. D."]},{"key":"dc:title","label":"Title","values":["Micromechanical Aspects of Aging in Granular Soils"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Brandon, Thomas L.","Mitchell, James K."],"dc:contributor.committeemember":["Green, Russell A.","Filz, George M."],"dc:contributor.department":["Civil Engineering"],"dc:creator":["Suarez Zambrano, Nestor Ricardo"],"dc:date.accessioned":["2014-03-14T20:16:31Z"],"dc:date.available":["2014-03-14T20:16:31Z","2012-11-09"],"dc:date.issued":["2012-09-03"],"dc:description.abstract":["Granular soils exhibit a generally beneficial change in engineering properties with time after deposition or densification, during a process commonly known as aging. Soil properties reported to change during aging include the small strain modulus and stiffness, penetration resistance, liquefaction resistance, and pile setup. 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