Principle and practice of hydraulic softening top-cutting and pressure relief technology in weakly cemented strata
Extremely thick and hard roofs are difficult to break in the mining of a working face, and the large area of the suspended roof easily induces a strong ground pressure or dynamic impact disasters. The roof control of a coal mining face in a mine in western China was taken as a case study. The minera...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2024-02-01
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| Series: | Frontiers in Earth Science |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2024.1367933/full |
| _version_ | 1797294136329502720 |
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| author | Tao Wang Guoyao Xu Liyuan Liu Chaoqiang Bai Weiwei Ye Lihui Sun |
| author_facet | Tao Wang Guoyao Xu Liyuan Liu Chaoqiang Bai Weiwei Ye Lihui Sun |
| author_sort | Tao Wang |
| collection | DOAJ |
| description | Extremely thick and hard roofs are difficult to break in the mining of a working face, and the large area of the suspended roof easily induces a strong ground pressure or dynamic impact disasters. The roof control of a coal mining face in a mine in western China was taken as a case study. The mineral composition, microstructure, and hydrophysical properties of the hard roof overlying the coal seam were analyzed. The characteristics of the weak-cementation strata that are prone to mud and collapse when encountering water were targeted to investigate the hydraulic softening roof-cutting and pressure relief technology. It was found that the clay mineral composition in the roof plate accounts for 60.6%. After 24 h of natural immersion, the rock strength decreased by approximately 10.3%–49%, and further immersion caused disintegration. By arranging high and low double-row water injection softening drilling holes in the cutting hole and roadway of the working face, the strength of roof rock strata in the target area was reduced, and the initial weighting step distance and weighting strength of the working face were reduced. The hydraulic softening roof-cutting pressure relief technology effectively regulated the weighting step distance of the hard roof and the peak weighting of the working face. |
| first_indexed | 2024-03-07T21:25:52Z |
| format | Article |
| id | doaj.art-6ea84de670164697999cfd47949bc20e |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-03-07T21:25:52Z |
| publishDate | 2024-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-6ea84de670164697999cfd47949bc20e2024-02-27T04:59:20ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632024-02-011210.3389/feart.2024.13679331367933Principle and practice of hydraulic softening top-cutting and pressure relief technology in weakly cemented strataTao Wang0Guoyao Xu1Liyuan Liu2Chaoqiang Bai3Weiwei Ye4Lihui Sun5Beijing Key Laboratory of Urban Underground Space Engineering, School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing, ChinaBeijing Key Laboratory of Urban Underground Space Engineering, School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing, ChinaBeijing Key Laboratory of Urban Underground Space Engineering, School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing, ChinaBeijing Key Laboratory of Urban Underground Space Engineering, School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing, ChinaBeijing Key Laboratory of Urban Underground Space Engineering, School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing, ChinaSchool of Mining and Geomatics Engineering, Hebei University of Engineering, Handan, ChinaExtremely thick and hard roofs are difficult to break in the mining of a working face, and the large area of the suspended roof easily induces a strong ground pressure or dynamic impact disasters. The roof control of a coal mining face in a mine in western China was taken as a case study. The mineral composition, microstructure, and hydrophysical properties of the hard roof overlying the coal seam were analyzed. The characteristics of the weak-cementation strata that are prone to mud and collapse when encountering water were targeted to investigate the hydraulic softening roof-cutting and pressure relief technology. It was found that the clay mineral composition in the roof plate accounts for 60.6%. After 24 h of natural immersion, the rock strength decreased by approximately 10.3%–49%, and further immersion caused disintegration. By arranging high and low double-row water injection softening drilling holes in the cutting hole and roadway of the working face, the strength of roof rock strata in the target area was reduced, and the initial weighting step distance and weighting strength of the working face were reduced. The hydraulic softening roof-cutting pressure relief technology effectively regulated the weighting step distance of the hard roof and the peak weighting of the working face.https://www.frontiersin.org/articles/10.3389/feart.2024.1367933/fullweakly consolidated formationgiant thick roof platehydraulic softeningpressure relief techniqueroof-cutting |
| spellingShingle | Tao Wang Guoyao Xu Liyuan Liu Chaoqiang Bai Weiwei Ye Lihui Sun Principle and practice of hydraulic softening top-cutting and pressure relief technology in weakly cemented strata Frontiers in Earth Science weakly consolidated formation giant thick roof plate hydraulic softening pressure relief technique roof-cutting |
| title | Principle and practice of hydraulic softening top-cutting and pressure relief technology in weakly cemented strata |
| title_full | Principle and practice of hydraulic softening top-cutting and pressure relief technology in weakly cemented strata |
| title_fullStr | Principle and practice of hydraulic softening top-cutting and pressure relief technology in weakly cemented strata |
| title_full_unstemmed | Principle and practice of hydraulic softening top-cutting and pressure relief technology in weakly cemented strata |
| title_short | Principle and practice of hydraulic softening top-cutting and pressure relief technology in weakly cemented strata |
| title_sort | principle and practice of hydraulic softening top cutting and pressure relief technology in weakly cemented strata |
| topic | weakly consolidated formation giant thick roof plate hydraulic softening pressure relief technique roof-cutting |
| url | https://www.frontiersin.org/articles/10.3389/feart.2024.1367933/full |
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