Height-limited mining with intelligent coal drawing technology on aquifers protection in ultra-thick coal seams

Height-limited mining with intelligent coal drawing technology on aquifers protection in ultra-thick coal seams | 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 Research Article Height-limited mining with intelligent coal drawing technology on aquifers protection in ultra-thick coal seams Yang Li, Yucheng Wang, Tiezheng Li, Xinghai Lei, Shuo Zhang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7449149/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract To address the challenge of controlling the drawing height in top coal caving mining under aquifers within ultra-thick coal seams, this study employed an integrated approach combining theoretical analysis, numerical simulation, and field testing at I0216302 working face of Mindong No.1 Mine. The results demonstrate that coal drawing is influenced by several key parameters: coal drawing angle, axis deflection angle, eccentricity, and horizontal distance from the drawing outlet to the coal break line. Specifically, the axis deflection angle follows an exponential relationship with drawing time, and the drawing body height exhibits logistic growth relative to time. The coal drawing process also exhibits dynamic evolution of multi-layered force chain arches that continuously form and collapse. Force blocks evolve through strong-to-weak arch transitions, with distinct spatial distributions: strong arches predominantly develop within 5-8 m ahead of the face and above hydraulic supports in the goaf area, while weak arches are confined near the drawing outlet. These force chain structures significantly influence drawing velocity by creating periodic resistance variations during arch collapse, causing particle speed fluctuations between 0.10–0.21 m/s. Regarding geometric morphology, when the drawing height is less than 2 times coal cutting height, the drawing body assumes a prolate ellipsoid shape with vertical-dominated development, where particles directly above the outlet move fastest. At 2–3 times coal cutting height, it transitions to an oblate ellipsoid with lateral-dominated flow, accelerating particles toward the upper-right goaf and upper-left canopy regions. Through the intelligent coal drawing system, by setting the coal cutting height at 3 m and the coal drawing time at 110 s, the coal drawing height can be controlled within 6 m, and fractured zone height can be maintained within 85 m. This effectively prevents water and sand inrush accidents during extraction. Ultra-thick coal seam Height-limited mining Top coal movement Intelligent coal drawing Aquifers protection Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-7449149","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":602176351,"identity":"b021595a-5ced-464c-b767-bc1b4c3d252c","order_by":0,"name":"Yang Li","email":"","orcid":"","institution":"China University of Mining and Technology - Beijing","correspondingAuthor":false,"prefix":"","firstName":"Yang","middleName":"","lastName":"Li","suffix":""},{"id":602176352,"identity":"c0f255b6-603a-46c3-966d-3f09d2b271d2","order_by":1,"name":"Yucheng Wang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA1klEQVRIiWNgGAWjYBACNvaG9A8feNjq7RsOHyBOCx/PgWeMM2T4EgwYjyUQp0VOIvEZM4+NXIIB8xkDIh3GczjtMU+OWZ4525mPN94w2MnpNhDSwt6WbjjnTFqxZc/ZzZZzGJKNzQ4QtOVMgsTbnmOMDTfObpPmYTiQuI2gFon8DxK8//4zNtx/84xYLQlpkjw8bIkbDpxhI1ILz4Fkwxk8bMaSDceMLecYEOEX+faGxAfAqJTjZzj88MabCjs5glpQgAQPkVGDrIVUHaNgFIyCUTAiAAASWUZKVAPq6QAAAABJRU5ErkJggg==","orcid":"","institution":"China University of Mining and Technology - Beijing","correspondingAuthor":true,"prefix":"","firstName":"Yucheng","middleName":"","lastName":"Wang","suffix":""},{"id":602176353,"identity":"4f790b22-f995-4518-aeff-e58325c9fa3a","order_by":2,"name":"Tiezheng Li","email":"","orcid":"","institution":"China University of Mining and Technology - Beijing","correspondingAuthor":false,"prefix":"","firstName":"Tiezheng","middleName":"","lastName":"Li","suffix":""},{"id":602176354,"identity":"aef0d7f2-d820-4e0a-8fad-982fa3843da0","order_by":3,"name":"Xinghai Lei","email":"","orcid":"","institution":"China University of Mining and Technology - Beijing","correspondingAuthor":false,"prefix":"","firstName":"Xinghai","middleName":"","lastName":"Lei","suffix":""},{"id":602176355,"identity":"eab089a0-c537-4012-9acc-8117ce3ca4a9","order_by":4,"name":"Shuo Zhang","email":"","orcid":"","institution":"China University of Mining and Technology - Beijing","correspondingAuthor":false,"prefix":"","firstName":"Shuo","middleName":"","lastName":"Zhang","suffix":""}],"badges":[],"createdAt":"2025-08-25 03:08:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7449149/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7449149/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104808306,"identity":"c2ef13b3-1e3b-4595-9807-17845f25e194","added_by":"auto","created_at":"2026-03-17 12:35:43","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2805546,"visible":true,"origin":"","legend":"","description":"","filename":"Wyc.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7449149/v1_covered_1b0ea7a5-b5bf-4305-a7d3-3a2dc0f69ef9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Height-limited mining with intelligent coal drawing technology on aquifers protection in ultra-thick coal seams","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Ultra-thick coal seam, Height-limited mining, Top coal movement, Intelligent coal drawing, Aquifers protection","lastPublishedDoi":"10.21203/rs.3.rs-7449149/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7449149/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"To address the challenge of controlling the drawing height in top coal caving mining under aquifers within ultra-thick coal seams, this study employed an integrated approach combining theoretical analysis, numerical simulation, and field testing at I0216302 working face of Mindong No.1 Mine. The results demonstrate that coal drawing is influenced by several key parameters: coal drawing angle, axis deflection angle, eccentricity, and horizontal distance from the drawing outlet to the coal break line. Specifically, the axis deflection angle follows an exponential relationship with drawing time, and the drawing body height exhibits logistic growth relative to time. The coal drawing process also exhibits dynamic evolution of multi-layered force chain arches that continuously form and collapse. Force blocks evolve through strong-to-weak arch transitions, with distinct spatial distributions: strong arches predominantly develop within 5-8 m ahead of the face and above hydraulic supports in the goaf area, while weak arches are confined near the drawing outlet. These force chain structures significantly influence drawing velocity by creating periodic resistance variations during arch collapse, causing particle speed fluctuations between 0.10–0.21 m/s. Regarding geometric morphology, when the drawing height is less than 2 times coal cutting height, the drawing body assumes a prolate ellipsoid shape with vertical-dominated development, where particles directly above the outlet move fastest. At 2–3 times coal cutting height, it transitions to an oblate ellipsoid with lateral-dominated flow, accelerating particles toward the upper-right goaf and upper-left canopy regions. Through the intelligent coal drawing system, by setting the coal cutting height at 3 m and the coal drawing time at 110 s, the coal drawing height can be controlled within 6 m, and fractured zone height can be maintained within 85 m. 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