{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/44801"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/44801","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Optimizing secondary tailgate support selection","abstract":"A model was developed to facilitate secondary tailgate support selection based on analysis of a data base of over 100 case studies compiled from two different surveys of operating longwall coal mines in the United States. The ALPS (Analysis of Long wall Pillar Stability) program was used to determine adequacy of pillar design for the successful longwall case histories. A relationship was developed between the secondary support density necessary to maintain a stable tailgate entry during mining and the CMRR (Coal Mine Roof Rating). This relationship defines the lower bound of secondary support density currently used in longwall mines. The model used only successful tailgate case history data with adequate ALPS SF according to the CMRR for each case. This model facilitates mine design by predicting secondary support density required for a tailgate entry depending on the ALPS SF and CMRR, which can result in significant economic benefits.","abstract_html":"A model was developed to facilitate secondary tailgate support selection based on analysis of a data base of over 100 case studies compiled from two different surveys of operating longwall coal mines in the United States. The ALPS (Analysis of Long wall Pillar Stability) program was used to determine adequacy of pillar design for the successful longwall case histories. A relationship was developed between the secondary support density necessary to maintain a stable tailgate entry during mining and the CMRR (Coal Mine Roof Rating). This relationship defines the lower bound of secondary support density currently used in longwall mines. The model used only successful tailgate case history data with adequate ALPS SF according to the CMRR for each case. This model facilitates mine design by predicting secondary support density required for a tailgate entry depending on the ALPS SF and CMRR, which can result in significant economic benefits.","abstract_has_math":false,"creators":["Harwood, Cary P."],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Mining and Minerals Engineering","degree_department":"Mining and Minerals Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Haycocks, Christopher"],"committee_members":["Karmis, Michael E.","Luttrell, Gerald H."],"year":1996,"date_issued":"1996-06-12","date_published":"1996-06-12","updated_at":"2026-07-22T22:20:20Z","subjects":["coal mining","Longwall","tailgate","secondary support","capacity"],"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":["etd-09182008-063231"],"render_values":[{"text":"etd-09182008-063231","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/44801","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Haycocks, Christopher"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Karmis, Michael E.","Luttrell, Gerald H."]},{"key":"dc:contributor.department","label":"Department","values":["Mining and Minerals Engineering"]},{"key":"dc:creator","label":"Author","values":["Harwood, Cary P."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:45:57Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:45:57Z","2008-09-18"]},{"key":"dc:date.issued","label":"Date","values":["1996-06-12"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mining and Minerals Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"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":["coal mining","Longwall","tailgate","secondary support","capacity"]}]},{"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":["etd-09182008-063231"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/44801"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A model was developed to facilitate secondary tailgate support selection based on analysis of a data base of over 100 case studies compiled from two different surveys of operating longwall coal mines in the United States. 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This model facilitates mine design by predicting secondary support density required for a tailgate entry depending on the ALPS SF and CMRR, which can result in significant economic benefits."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["BTD"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Optimizing secondary tailgate support selection"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Haycocks, Christopher"],"dc:contributor.committeemember":["Karmis, Michael E.","Luttrell, Gerald H."],"dc:contributor.department":["Mining and Minerals Engineering"],"dc:creator":["Harwood, Cary P."],"dc:date.accessioned":["2014-03-14T21:45:57Z"],"dc:date.available":["2014-03-14T21:45:57Z","2008-09-18"],"dc:date.issued":["1996-06-12"],"dc:description.abstract":["A model was developed to facilitate secondary tailgate support selection based on analysis of a data base of over 100 case studies compiled from two different surveys of operating longwall coal mines in the United States. 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