Investigating the Width of Isolated Coal Pillars in Deep Hard-Strata Mines for Prevention of Mine Seismicity and Rockburst
Abstract
:1. Introduction
2. Case Study of Mining-Induced Seismicity on Both Sides of an ICP
2.1. Field Conditions of Yingpanhao Coal Mine in Inner Mongolia
2.2. Description of Mine Seismicity on the Working Face
3. Occurrence Mechanism of MS on Both Sides of an ICP
3.1. Flexural Deformation of the MKS
3.2. Mining-Induced Compression Amount of the ICP
3.3. Analysis of the Relationship Between the Compression of the ICP and the Flexural Deformation of the MKS
- (1)
- When wmax ≥ s, the overlying high hard MKS undergoes a flexural deformation, but it still keeps full contact with the lower rock strata, supported by the ICP. This means that its flexural deformation does not reach the limited deflection and breaks will not arise.
- (2)
- When wmax < s, after ICP experiences a compressive deformation, the soft rock stratum breaks and dips down, MKS reaches its limited deflection, and a separated stratum with a large amount of elastic energy appears. Influenced by other disturbances, it easily breaks down, releases a great amount of energy, and leads to MS, which greatly affects the safety of underground production and the stability of ground buildings.
4. ICP Width Design Based on the Collaborative Control of MS and Rockburst
4.1. Width of the ICP Calculated Based on the Nonoccurrence of OII Rockbursts
4.2. ICP Width Calculated Based on MS Prevention
4.3. ICP Width Design Basis
- (1)
- If , both OII rockbursts and MS may be induced;
- (2)
- If , either OII rockbursts or MS may be induced;
- (3)
- If , neither OII rockbursts nor MS will take place.
5. Verification by Theoretical Solution, Numerical Simulation Analysis, and Microseismic Monitoring
5.1. Verification by Theoretical Solution
5.2. Verification by Numerical Simulation Analysis
5.3. Verification by Microseismic Monitoring Analysis
6. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Names of the Rocks | Thickness/m | Accumulated Depth/m | Columnar Forms | Note |
---|---|---|---|---|
Wind-blown sand | 95.75 | 95.75 | Sand on the surface | |
Sandstone group | 324.45 | 420.2 | (Red layer) MKS | |
Interbedding of sandy mudstone and sandstone | 213.81 | 634.01 | Soft rock strata | |
Sandstone group | 38.55 | 672.56 | Inferior key stratum | |
Sandy mudstone | 7.52 | 680.08 | Soft rock stratum | |
Medium sandstone | 19.47 | 699.55 | Basic roof | |
Siltstone | 14.79 | 714.34 | ||
2-2 coal | 6.13 | 720.47 | Coal seam | |
Siltstone | 9.21 | 729.68 | Basic bottom |
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Wang, B.; Zhu, S.; Jiang, F.; Liu, J.; Shang, X.; Zhang, X. Investigating the Width of Isolated Coal Pillars in Deep Hard-Strata Mines for Prevention of Mine Seismicity and Rockburst. Energies 2020, 13, 4293. https://doi.org/10.3390/en13174293
Wang B, Zhu S, Jiang F, Liu J, Shang X, Zhang X. Investigating the Width of Isolated Coal Pillars in Deep Hard-Strata Mines for Prevention of Mine Seismicity and Rockburst. Energies. 2020; 13(17):4293. https://doi.org/10.3390/en13174293
Chicago/Turabian StyleWang, Bo, Sitao Zhu, Fuxing Jiang, Jinhai Liu, Xiaoguang Shang, and Xiufeng Zhang. 2020. "Investigating the Width of Isolated Coal Pillars in Deep Hard-Strata Mines for Prevention of Mine Seismicity and Rockburst" Energies 13, no. 17: 4293. https://doi.org/10.3390/en13174293