Numerical Study on Characteristics of Bedrock and Surface Failure in Mining of Shallow-Buried MCS
Coal is one of the important energy sources for industry. When it is mined, it will cause the destruction of bedrock and surface. However, it is more severe in mining shallow-buried multi coal seams (SBMCS). To better reveal the characteristics of the bedrock and surface damage, we have carried out...
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MDPI AG
2022-05-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/15/9/3446 |
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| author | Guangchun Liu Wenzhi Zhang Youfeng Zou Huabin Chai Yongan Xue |
| author_facet | Guangchun Liu Wenzhi Zhang Youfeng Zou Huabin Chai Yongan Xue |
| author_sort | Guangchun Liu |
| collection | DOAJ |
| description | Coal is one of the important energy sources for industry. When it is mined, it will cause the destruction of bedrock and surface. However, it is more severe in mining shallow-buried multi coal seams (SBMCS). To better reveal the characteristics of the bedrock and surface damage, we have carried out a theoretical analysis, as well as used numerical simulations and field monitoring methods to study the surface and bedrock damage caused by the mining of SBMCS. The characteristics of bedrock and surface failure structure, settlement, and stress distribution were studied and analyzed. The findings show that the collapsed block, formed by the rupture of the overlying stratum, interacts with the surrounding rock to form large cavities and gaps, and the stress concentration occurs between them. The maximum downward vertical concentration stress is about 9.79 MPa. The mining of the lower coal seam can lead to repeated failure of the upper bedrock and goaf. The settlement of bedrock presents gradient change, and the settlement of upper bedrock is large, about 8.0 m, and the maximum settlement is 8.183 m, while that of lower bedrock is small and about 3.5–4.0 m. The weak rock stratum in the bedrock is crushed by the change stress of repeated mining, and formed a broken rock stratum. The cracks in the bedrock develop directly to the ground. On the ground, tensile cracks, compression uplift, stepped cracks, and even collapse pits are easy to cause in mining SBMCS. Affected by repeated mining, the variation of surface vertical stress is complex and disorderly in the middle of the basin, and the variation of horizontal stress is mainly concentrated on the edge of the basin. The maximum stress reaches 100 KPa, and the minimum stress is about 78 KPa. Through theoretical analysis and discussion, the size of the key blocks is directly related to the thickness and strength of the rock stratum. |
| first_indexed | 2024-03-10T04:11:23Z |
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| id | doaj.art-a5e968ac2df846a08ee1bbccbf7247c0 |
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| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-10T04:11:23Z |
| publishDate | 2022-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-a5e968ac2df846a08ee1bbccbf7247c02023-11-23T08:11:25ZengMDPI AGEnergies1996-10732022-05-01159344610.3390/en15093446Numerical Study on Characteristics of Bedrock and Surface Failure in Mining of Shallow-Buried MCSGuangchun Liu0Wenzhi Zhang1Youfeng Zou2Huabin Chai3Yongan Xue4School of Surveying and Land Information, Henan Polytechnic University, Jiaozuo 454000, ChinaSchool of Surveying and Land Information, Henan Polytechnic University, Jiaozuo 454000, ChinaSchool of Surveying and Land Information, Henan Polytechnic University, Jiaozuo 454000, ChinaSchool of Surveying and Land Information, Henan Polytechnic University, Jiaozuo 454000, ChinaSchool of Surveying and Land Information, Henan Polytechnic University, Jiaozuo 454000, ChinaCoal is one of the important energy sources for industry. When it is mined, it will cause the destruction of bedrock and surface. However, it is more severe in mining shallow-buried multi coal seams (SBMCS). To better reveal the characteristics of the bedrock and surface damage, we have carried out a theoretical analysis, as well as used numerical simulations and field monitoring methods to study the surface and bedrock damage caused by the mining of SBMCS. The characteristics of bedrock and surface failure structure, settlement, and stress distribution were studied and analyzed. The findings show that the collapsed block, formed by the rupture of the overlying stratum, interacts with the surrounding rock to form large cavities and gaps, and the stress concentration occurs between them. The maximum downward vertical concentration stress is about 9.79 MPa. The mining of the lower coal seam can lead to repeated failure of the upper bedrock and goaf. The settlement of bedrock presents gradient change, and the settlement of upper bedrock is large, about 8.0 m, and the maximum settlement is 8.183 m, while that of lower bedrock is small and about 3.5–4.0 m. The weak rock stratum in the bedrock is crushed by the change stress of repeated mining, and formed a broken rock stratum. The cracks in the bedrock develop directly to the ground. On the ground, tensile cracks, compression uplift, stepped cracks, and even collapse pits are easy to cause in mining SBMCS. Affected by repeated mining, the variation of surface vertical stress is complex and disorderly in the middle of the basin, and the variation of horizontal stress is mainly concentrated on the edge of the basin. The maximum stress reaches 100 KPa, and the minimum stress is about 78 KPa. Through theoretical analysis and discussion, the size of the key blocks is directly related to the thickness and strength of the rock stratum.https://www.mdpi.com/1996-1073/15/9/3446coal miningmulti coal seamCDEMnumerical simulationbedrock failuresurface damage |
| spellingShingle | Guangchun Liu Wenzhi Zhang Youfeng Zou Huabin Chai Yongan Xue Numerical Study on Characteristics of Bedrock and Surface Failure in Mining of Shallow-Buried MCS Energies coal mining multi coal seam CDEM numerical simulation bedrock failure surface damage |
| title | Numerical Study on Characteristics of Bedrock and Surface Failure in Mining of Shallow-Buried MCS |
| title_full | Numerical Study on Characteristics of Bedrock and Surface Failure in Mining of Shallow-Buried MCS |
| title_fullStr | Numerical Study on Characteristics of Bedrock and Surface Failure in Mining of Shallow-Buried MCS |
| title_full_unstemmed | Numerical Study on Characteristics of Bedrock and Surface Failure in Mining of Shallow-Buried MCS |
| title_short | Numerical Study on Characteristics of Bedrock and Surface Failure in Mining of Shallow-Buried MCS |
| title_sort | numerical study on characteristics of bedrock and surface failure in mining of shallow buried mcs |
| topic | coal mining multi coal seam CDEM numerical simulation bedrock failure surface damage |
| url | https://www.mdpi.com/1996-1073/15/9/3446 |
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