Research on water immersion damage characteristics and equivalent width of coal pillar

Research on water immersion damage characteristics and equivalent width of coal pillar | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Research on water immersion damage characteristics and equivalent width of coal pillar Zhixian SHI, Guangan ZHU, Zekai ZI This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5298081/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 28 Dec, 2024 Read the published version in Scientific Reports → Version 1 posted 10 You are reading this latest preprint version Abstract Affected by weakening effect of water in the goaf, the bearing capacity of coal pillar reduced, and coal pillar rock burst is prone to occur, which is a serious threat to mine safety in production. In order to study the equivalent width and stability of coal pillar in water-rich coal seam, taking the section coal pillar of a working face as the research object, combined with laboratory test, theoretical analysis, simulation and engineering practice, the stress, elastic core area width, damage degree and energy accumulation of 36m water-immersed coal pillar and 26m, 28m, 30m, 32m, 36m unimmersed coal pillars are analyzed. The research results show that: (1) The reasonable width of coal pillar under flooded and unflooded conditions is 36.09m and 29.58m, respectively. The width has been reduced by 6.19m under flooded condition. The peak stress value in the goaf and the side of the working face and the range of stress curve in the elastic core area are similar between 36m water-immersed coal pillar and 30m unimmersed coal pillar. The bearing capacity of the two is equivalent, which is consistent with theoretical analysis. (2) The coupling relationship between flooding and damage of coal pillar can be divided into three stages with the increase of iteration times. Firstly, the flooding area in the early stage of the coal pillar is the damage area caused by the excavation working face, and the flooding rate is fast. Secondly, the mechanical parameters of the coal pillar decrease after water immersion, resulting in the increase of the damage area of the coal pillar. In turn, water permeates into the coal pillar, and the rate of immersion is slower. Finally, the flooded area of the coal pillar remains unchanged from the damaged area. (3) After the 36m coal pillar was immersed in water, the peak stress of the side coal pillar in the goaf decreased by 7.66%. And as the number of iterations increases, the distance of the coal pillar "wedge" high energy area is gradually shortened. The damage rate experienced three stages: rapid, slow, and stopped increasing. The bearing capacity of coal pillar decreases after water immersion softening (4) The widths of the elastic core areas in the upper, middle and lower parts of the 36m water-immersed coal pillar and 30m unimmersed coal pillar are 20, 14.5, 12m and 18, 14, 11m respectively, which are relatively close and greater than the critical width of the coal pillar. The actual damage degree of both is greater than the critical damage degree. The elastic strain energy densities of coal pillars are 191 and 187kJ/m 3 , respectively, showing wedge-shaped distribution. The carrying capacity of 36m water-immersed coal pillar and 30m unimmersed coal pillar is equivalent and stable. (5) Under the geological condition, the energy accumulation and distribution form of coal pillar with a width less than 30m is "cup-shaped". The risk of rock burst is higher. When the coal pillar is greater than 30m, coal pillar energy is distributed in two "wedges". The stability of coal pillar is enhanced, The risk of rock burst is reduced. The research can provide a reference for determining the reasonable width of section coal pillar in the water-rich rock burst coal seam in Binchang mining area. Physical sciences/Energy science and technology Physical sciences/Engineering water-immersed coal pillar equivalent width rock burst stability damage degree Full Text Additional Declarations No competing interests reported. Supplementary Files Supplementarydata.rar Cite Share Download PDF Status: Published Journal Publication published 28 Dec, 2024 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 14 Nov, 2024 Reviews received at journal 13 Nov, 2024 Reviewers agreed at journal 11 Nov, 2024 Reviews received at journal 11 Nov, 2024 Reviewers agreed at journal 08 Nov, 2024 Reviewers invited by journal 08 Nov, 2024 Editor assigned by journal 08 Nov, 2024 Editor invited by journal 08 Nov, 2024 Submission checks completed at journal 06 Nov, 2024 First submitted to journal 20 Oct, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5298081","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":378265755,"identity":"f648df28-da3b-4624-87e2-b6d6d18a0e4b","order_by":0,"name":"Zhixian SHI","email":"","orcid":"","institution":"Xi’an University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Zhixian","middleName":"","lastName":"SHI","suffix":""},{"id":378265758,"identity":"731f5316-340c-43f2-b8fc-b7665aee23fc","order_by":1,"name":"Guangan ZHU","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA10lEQVRIiWNgGAWjYDACCTiL+cCBDz9I08KWeHBmD2laeIwPc7ARoUN+do/xa56aO3b9s3s+HGbgYZDnFzuAXwvjnDNm1jzHniXPuHN2w+ECCwbDmbMT8GthlsgxM+ZhO5zMcCN3w+EZPAwJBrcJaGEDa/l3OFn+Rs6DwzxsRGjhkcgxfszbdtjO4EYOA3FaJCTSyhjn9h1OMLyRZgAMZAnCfpGfkbz5w5tvh+3lbiQ//vDhh408vzQBLWDvAInEBqitBJWDAPMHIGFPlNJRMApGwSgYmQAAwwBG6b2sqikAAAAASUVORK5CYII=","orcid":"","institution":"Xi’an University of Science and Technology","correspondingAuthor":true,"prefix":"","firstName":"Guangan","middleName":"","lastName":"ZHU","suffix":""},{"id":378265760,"identity":"3779d3c1-1fe1-40d9-882f-9aaf241549cf","order_by":2,"name":"Zekai ZI","email":"","orcid":"","institution":"Xi’an University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Zekai","middleName":"","lastName":"ZI","suffix":""}],"badges":[],"createdAt":"2024-10-20 11:23:09","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5298081/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5298081/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-024-83322-6","type":"published","date":"2024-12-28T15:56:55+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":72640768,"identity":"038a2fbc-4612-4379-8f74-619b4db09321","added_by":"auto","created_at":"2024-12-30 16:09:40","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1590578,"visible":true,"origin":"","legend":"","description":"","filename":"Researchonwaterimmersiondamagecharacteristicsandequivalentwidthofcoalpillar.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5298081/v1_covered_e9fbb7ce-da2e-4464-b4a6-9c277185bd20.pdf"},{"id":69378322,"identity":"20020c39-b500-4b34-984f-3c0892468ba8","added_by":"auto","created_at":"2024-11-19 17:47:36","extension":"rar","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":27874684,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarydata.rar","url":"https://assets-eu.researchsquare.com/files/rs-5298081/v1/ec6263afbd04e777c3e0ba53.rar"}],"financialInterests":"No competing interests reported.","formattedTitle":"Research on water immersion damage characteristics and equivalent width of coal pillar","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"water-immersed coal pillar, equivalent width, rock burst, stability, damage degree","lastPublishedDoi":"10.21203/rs.3.rs-5298081/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5298081/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAffected by weakening effect of water in the goaf, the bearing capacity of coal pillar reduced, and coal pillar rock burst is prone to occur, which is a serious threat to mine safety in production. In order to study the equivalent width and stability of coal pillar in water-rich coal seam, taking the section coal pillar of a working face as the research object, combined with laboratory test, theoretical analysis, simulation and engineering practice, the stress, elastic core area width, damage degree and energy accumulation of 36m water-immersed coal pillar and 26m, 28m, 30m, 32m, 36m unimmersed coal pillars are analyzed. The research results show that: (1) The reasonable width of coal pillar under flooded and unflooded conditions is 36.09m and 29.58m, respectively. The width has been reduced by 6.19m under flooded condition. The peak stress value in the goaf and the side of the working face and the range of stress curve in the elastic core area are similar between 36m water-immersed coal pillar and 30m unimmersed coal pillar. The bearing capacity of the two is equivalent, which is consistent with theoretical analysis. (2) The coupling relationship between flooding and damage of coal pillar can be divided into three stages with the increase of iteration times. Firstly, the flooding area in the early stage of the coal pillar is the damage area caused by the excavation working face, and the flooding rate is fast. Secondly, the mechanical parameters of the coal pillar decrease after water immersion, resulting in the increase of the damage area of the coal pillar. In turn, water permeates into the coal pillar, and the rate of immersion is slower. Finally, the flooded area of the coal pillar remains unchanged from the damaged area. (3) After the 36m coal pillar was immersed in water, the peak stress of the side coal pillar in the goaf decreased by 7.66%. And as the number of iterations increases, the distance of the coal pillar \"wedge\" high energy area is gradually shortened. The damage rate experienced three stages: rapid, slow, and stopped increasing. The bearing capacity of coal pillar decreases after water immersion softening (4) The widths of the elastic core areas in the upper, middle and lower parts of the 36m water-immersed coal pillar and 30m unimmersed coal pillar are 20, 14.5, 12m and 18, 14, 11m respectively, which are relatively close and greater than the critical width of the coal pillar. The actual damage degree of both is greater than the critical damage degree. The elastic strain energy densities of coal pillars are 191 and 187kJ/m\u003csup\u003e3\u003c/sup\u003e, respectively, showing wedge-shaped distribution. The carrying capacity of 36m water-immersed coal pillar and 30m unimmersed coal pillar is equivalent and stable. (5) Under the geological condition, the energy accumulation and distribution form of coal pillar with a width less than 30m is \"cup-shaped\". The risk of rock burst is higher. When the coal pillar is greater than 30m, coal pillar energy is distributed in two \"wedges\". The stability of coal pillar is enhanced, The risk of rock burst is reduced. The research can provide a reference for determining the reasonable width of section coal pillar in the water-rich rock burst coal seam in Binchang mining area.\u003c/p\u003e","manuscriptTitle":"Research on water immersion damage characteristics and equivalent width of coal pillar","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-11-19 17:47:26","doi":"10.21203/rs.3.rs-5298081/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-11-14T17:39:53+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-11-13T07:04:37+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"218396411107168334731239401307239740249","date":"2024-11-12T01:08:21+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-11-12T01:05:30+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"174807890951766665753399703366638745378","date":"2024-11-09T00:08:20+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-11-08T09:17:21+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-11-08T09:00:28+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-11-08T06:22:15+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-11-06T06:21:06+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2024-10-20T11:09:17+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"2d217dac-00a7-4f34-871d-cf8a531def06","owner":[],"postedDate":"November 19th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":40281836,"name":"Physical sciences/Energy science and technology"},{"id":40281837,"name":"Physical sciences/Engineering"}],"tags":[],"updatedAt":"2024-12-30T16:04:01+00:00","versionOfRecord":{"articleIdentity":"rs-5298081","link":"https://doi.org/10.1038/s41598-024-83322-6","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2024-12-28 15:56:55","publishedOnDateReadable":"December 28th, 2024"},"versionCreatedAt":"2024-11-19 17:47:26","video":"","vorDoi":"10.1038/s41598-024-83322-6","vorDoiUrl":"https://doi.org/10.1038/s41598-024-83322-6","workflowStages":[]},"version":"v1","identity":"rs-5298081","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5298081","identity":"rs-5298081","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}