Mine Strata Pressure Characteristics and Mechanisms in Gob-Side Entry Retention by Roof Cutting under Medium-Thick Coal Seam and Compound Roof Conditions
Abstract
:1. Introduction
2. General Situation of the Project
3. The Gob-Side Entry Retaining by Roof Cutting (GERRC) Technique
3.1. Technological Process
3.2. Entry Retaining Design
3.2.1. Design of Roof Cutting
3.2.2. Design of Entry Support
4. Monitoring of Mine Pressure
4.1. Pressure Monitoring Design for the Longwall Working Face
4.2. Gateway Pressure Monitoring Design
4.3. Pressure Monitoring Results
4.3.1. Pressure Monitoring Results for the Longwall Working Face
4.3.2. Gateway Pressure Monitoring Results
5. Mechanism of Overlying Strata Pressure
5.1. Mechanism of Longwall Working Face Pressure
5.1.1. Analysis of Roof Structure
5.1.2. Analysis of Weighting Characteristics
5.2. Mechanism of Gateroad Pressure
5.2.1. Coal Support Area
5.2.2. Dynamic Pressure Area
5.2.3. Stable Entry Area
6. Conclusions
Author Contributions
Funding
Conflicts of Interest
References
- Torres-Fuchslocher, C. Understanding the development of technology-intensive suppliers in resource-based developing economies. Res. Policy 2010, 39, 268–277. [Google Scholar] [CrossRef]
- Löschel, A. Technological change in economic models of environmental policy: A survey. Ecol. Econ. 2002, 43, 105–126. [Google Scholar] [CrossRef]
- Cristóbal, J.; Guillén-Gosálbez, G.; Jiménez, L.; Irabien, A. Optimization of global and local pollution control in electricity production from coal burning. Appl. Energy 2012, 92, 369–378. [Google Scholar]
- Zhou, N.; Levine, M.D.; Price, L. Overview of current energy-efficiency policies in China. Energy Policy 2010, 38, 6439–6452. [Google Scholar] [CrossRef]
- Tokimatsu, K.; Konishi, S.; Ishihara, K.; Tezuka, T.; Yasuoka, R.; Nishio, M. Role of innovative technologies under the global zero emissions scenarios. Appl. Energy 2016, 162, 1483–1493. [Google Scholar] [CrossRef]
- Ameri, M.; Mokhtari, H.; Sani, M.M. 4E analyses and multi-objective optimization of different fuels application for a large combined cycle power plant. Energy 2018, 156, 371–386. [Google Scholar] [CrossRef]
- Milici, R.C.; Flores, R.M.; Stricker, G.D. Coal resources, reserves and peak coal production in the United States. Int. J. Coal Geol. 2013, 113, 109–115. [Google Scholar] [CrossRef]
- Xue, Y. From tradition to modern times: evolution of coal mining technology in China. J. Hubei Polytech. Univ. (Humanit. Soc. Sci.) 2013, 30, 7–15. [Google Scholar]
- Jiao, H.B.; Zhao, A.G. The present situation of longwall mining technology in China and its application in thick coal seam. J. North China Inst. Sci. Technol. 2004, 5, 34–37. [Google Scholar]
- He, M.C.; Xie, H.P.; Peng, S.P.; Jiang, Y.D. Study on rock mechanics in deep mining engineering. Chin. J. Rock Mech. Eng. 2005, 24, 2803–2813. [Google Scholar]
- Kang, H.P.; Niu, D.L.; Zhang, Z.; Lin, J.; Li, Z.H.; Fan, M.J. Deformation characteristics of supporting rock and supporting technology of gob-side entry retaining in deep coal mine. Chin. J. Rock Mech. Eng. 2010, 29, 1977–1987. [Google Scholar]
- Suchowerska, A.M.; Merifield, R.S.; Carter, J.P. Vertical stress changes in multi-seam mining under supercritical longwall panels. Int. J. Rock Mech. Min. Sci. 2013, 61, 306–320. [Google Scholar] [CrossRef]
- Wang, J.G.; Wang, G. Discussion on gateway retained along goaf technology with roof breaking and pressure releasing. Coal Eng. 2012, 58, 24–26. (In Chinese) [Google Scholar]
- Howladar, M.F.; Karim, M.M. The selection of backfill materials for Barapukuria underground coal mine, Dinajpur, Bangladesh: Insight from the assessments of engineering properties of some selective materials. Environ. Earth Sci. 2015, 73, 6153–6165. [Google Scholar] [CrossRef]
- He, M.C.; Song, Z.Q.; Wang, A.; Yang, H.H.; Qi, H.G.; Guo, Z.G. Theory of longwall mining by using roof cutting shortwall team and 110 method—The third mining science and technology reform. Coal Sci. Technol. Mag. 2017, 37, 1–9. [Google Scholar]
- He, M.C.; Gao, Y.B.; Yang, J.; Gong, W.L. An innovative approach for gob-side entry retaining in thick coal seam longwall mining. Energies 2017, 10, 1785. [Google Scholar] [CrossRef]
- Qian, M.G.; Miao, X.X.; Xu, J.L. Theoretical study of key stratum in ground control. J. China Coal Soc. 1996, 21, 225–230. [Google Scholar]
- Song, Z.Q. The basic law of the overlying strata movement on the stope. J. Shandong Min. Inst. 1979, 1, 64–77. [Google Scholar]
- Jia, X.R.; Zhai, Y.D. A summary of theory and practice of sheet metal pressure in stope. Gr. Pressure Strata Control 1999, 15, 22–25. [Google Scholar]
- Zhao, G.J.; Qian, M.G. Behavior of overlying hard strata above working and its effect on roof pressure. J. China Coal Soc. 1987, 3, 1–8. [Google Scholar]
- Sun, X.M.; Liu, X.; Liang, G.F.; Wang, D.; Jiang, Y.L. Key Parameters of gob-side entry retaining formed by roof cut and pressure releasing in thin coal seams. Chin. J. Rock Mech. Eng. 2014, 33, 1449–1456. [Google Scholar]
- Gao, Y.B.; Guo, Z.B.; Yang, J.; Wang, J.W.; Wang, Y.J. Steady analysis of gob-side entry retaining formed by roof fracturing and control techniques by optimizing mine pressure. J. China Coal Soc. 2017, 42, 1672–1681. [Google Scholar]
- Guo, P.F.; Zhang, G.F.; Tao, Z.G. Blasting technology of gateway retaining along goaf pressure release by roof cutting in hard and weak complex roof. Coal Sci. Technol. 2016, 44, 120–124. (In Chinese) [Google Scholar]
- Song, L.B. Study on roof cutting, pressure released and gateway driving technology in Shendong Mining Area. Coal Sci. Technol. 2016, 44, 80–85. (In Chinese) [Google Scholar]
- Wang, Y.J.; Gao, Y.B.; Wang, E.Y.; He, M.C.; Yang, J. Roof deformation characteristics and preventive techniques using a novel non-pillar mining method of gob-side entry retaining by roof cutting. Energies 2018, 11, 627. [Google Scholar] [CrossRef]
- Ma, X.G.; He, M.C.; Wang, J.; Zhu, X.Q.; Li, C.L.; Zhang, J.B.; Jiang, Q.Q. Study on design of chamber supporting behind cutting hole under condition of gob-side entry retaining in 8304 face of Yanya coal mine. Coal Technol. 2017, 36, 30–33. [Google Scholar]
- He, M.C.; Guo, Z.B. Mechanical property and engineering application of anchor bolt with constant resistance and large deformation. Chin. J. Rock Mech. Eng. 2014, 33, 1297–1308. [Google Scholar]
- He, M.C.; Li, C.; Gong, W.L.; Wang, J.; Tao, Z.G. Support principles of NPR bolts/cables and control techniques of large deformation. Chin. J. Rock Mech. Eng. 2016, 35, 1513–1529. [Google Scholar]
- Zhao, Y.M.; Zhang, N.; Si, G.Y. A fiber bragg grating-based monitoring system for roof safety control in underground coal mining. Sensors 2016, 16, 1759. [Google Scholar] [CrossRef] [PubMed]
- Yang, K.; Kong, X.Y.; Lu, W.; Liu, S. Study of strata pressure behaviors with longwall mining in large inclination and thick coal seam under closed distance mined gob. Chin. J. Rock Mech. Eng. 2015, 34, 4278–4285. (In Chinese) [Google Scholar]
- Tan, Y.L. Mining Pressure and Strata Control; Coal Industry Press: Beijing, China, 2008. [Google Scholar]
- Li, H.M.; Jiang, D.J.; Li, D.Y. Analysis of ground pressure and roof movement in fully-mechanized top coal caving with large mining height in ultra-thick seam. J. China Coal Soc. 2014, 39, 1956–1960. (In Chinese) [Google Scholar]
- Chi, B.S.; Zhou, K.F.; He, M.C.; Yang, J.; Wang, Q.; Ma, X.G. Optimization research on supporting parameters of roof cutting entry retaining with large mining height face. Coal Sci. Technol. 2017, 45, 128–133. [Google Scholar]
- Xu, Y.; Zhou, H.; Bai, J.B.; Chen, J. Characteristics and control method of floor heave in gob-side entry retaining. Chin. J. Rock Mech. Eng. 2015, 34, 4235–4243. [Google Scholar]
- Gao, Y.B.; Liu, D.Q.; Zhang, X.Y.; He, M.C. Analysis and optimization of entry stability in underground longwall mining. Sustainability 2017, 9, 2079. [Google Scholar] [CrossRef]
- Shehpari, M. A review of underground mine backfilling methods with emphasis on cemented paste backfill. J. Geotech. Geoenviron. Eng. 2015, 20, 5183–5208. [Google Scholar]
- Hou, C.J.; Ma, N.J. Stress in in-seam roadway sides and limit equilibrium zone. J. China Coal Soc. 1989, 4, 21–29. [Google Scholar]
- Yang, H.B.; Wang, Z.G.; Zhao, Y.H.; Song, X.C. Study on roof control technology for withdrawal passageway in fully mechanized coal face with large mining height. Min. Saf. Environ. Prot. 2014, 10, 59–61. (In Chinese) [Google Scholar]
Lithology | Average Thickness/m | Compressive Strength/MPa | Tensile Strength/MPa | Internal Friction Angle/° | Cohesion/MPa | Bulk Modulus/GPa | Shear Modulus/GPa |
---|---|---|---|---|---|---|---|
Mudstone | 1.44 | 33 | 3.2 | 28 | 0.2 | 0.20 | 0.15 |
Fine sandstone | 5.46 | 60 | 7.3 | 32 | 1.0 | 3.81 | 3.05 |
Mudstone | 0.80 | 33 | 3.2 | 28 | 0.2 | 0.20 | 0.15 |
Medium sandstone | 2.89 | 77 | 8.4 | 33 | 2.6 | 11.49 | 7.26 |
Mudstone | 1.23 | 33 | 3.2 | 28 | 0.2 | 0.20 | 0.15 |
Medium sandstone | 1.30 | 77 | 8.4 | 33 | 2.6 | 11.49 | 7.26 |
Fine sandstone | 0.60 | 60 | 7.3 | 32 | 1.0 | 3.81 | 3.05 |
Siltstone | 1.38 | 45 | 4.3 | 32 | 0.8 | 2.11 | 1.86 |
Support Number | First Weighting Step/m | Periodic Weighting Step/m | Average Pressure/MPa | Peak Pressure/MPa | |||
---|---|---|---|---|---|---|---|
1 | 2 | 3 | Average | ||||
1 | 65 | 40 | 41 | 42 | 41 | 22.9 | 40.8 |
34 | 53 | 39 | 40 | 38 | 39 | 25.7 | 42.7 |
73 | 59 | 45 | 46 | 44 | 45 | 20.8 | 30.6 |
Sequence | Lithology | Average Thickness/m | Cumulative Thickness /m | Uncut Single Layer Pressure /kN | Uncut Cumulative Layer Pressure /kN | Cutting Single Layer Pressure /kN | Cutting Cumulative Layer Pressure /kN |
---|---|---|---|---|---|---|---|
① | Mudstone | 1.44 | 1.44 | 483.84 | 483.84 | 120.96 | 120.96 |
② | Fine sandstone | 5.46 | 6.90 | 15868.44 | 16352.28 | 3967.18 | 4088.14 |
③ | Mudstone | 0.80 | 7.70 | 149.38 | 16501.66 | 37.38 | 4125.52 |
④ | Medium sandstone | 2.89 | 10.59 | 5115.6 | 21617.26 | 1278.9 | 5404.42 |
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Ma, X.; He, M.; Wang, J.; Gao, Y.; Zhu, D.; Liu, Y. Mine Strata Pressure Characteristics and Mechanisms in Gob-Side Entry Retention by Roof Cutting under Medium-Thick Coal Seam and Compound Roof Conditions. Energies 2018, 11, 2539. https://doi.org/10.3390/en11102539
Ma X, He M, Wang J, Gao Y, Zhu D, Liu Y. Mine Strata Pressure Characteristics and Mechanisms in Gob-Side Entry Retention by Roof Cutting under Medium-Thick Coal Seam and Compound Roof Conditions. Energies. 2018; 11(10):2539. https://doi.org/10.3390/en11102539
Chicago/Turabian StyleMa, Xingen, Manchao He, Jiong Wang, Yubing Gao, Daoyong Zhu, and Yuxing Liu. 2018. "Mine Strata Pressure Characteristics and Mechanisms in Gob-Side Entry Retention by Roof Cutting under Medium-Thick Coal Seam and Compound Roof Conditions" Energies 11, no. 10: 2539. https://doi.org/10.3390/en11102539