International Scientific Journal


The fractures in coal and rock mass are the main channels of gas seepage, and understanding the gas migration law during mining is the precondition of gas control. The long-term in-situ monitoring of the abutment pressure, fracture networks and gas-flow in front of a mining face was carried out and the 1-D connectivity ratio of boreholes were calculated. The results showed that under the influence of mining, the fracture networks developed to the depth of rock stratum, and as far-field gas seepage channels, far-field gas continuously supplied the near-field gas. The gas flow in front of the mining face have undergone two stages of evolution from initial value to peak value, and then to a stable value. The 1-D connectivity ratio the abutment pressure about 5 to 10 m. The 1-D connectivity ratio reflected the dergree of coal and rock fracture penetration caused by mining, and the area with the highest gas extraction efficiency was the transition zone from peak abutment pressure to residual pressure in coal seams.
PAPER REVISED: 2018-09-13
PAPER ACCEPTED: 2018-12-21
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  1. Adhikary, D. P., et al., Modelling of Longwall Mining-Induced Strata Permeability Change, Rock Mechanics & Rock Engineering, 48(2015), 1, pp. 345-359
  2. Ma, H., et al., Research on the Disturbance Stress and the Movement Law of Gas in Coal Seam, Proceedings of the 22nd Safety Engineering National Annual Conference of Colleges, Huangshan, China, 2010, pp. 763-767.
  3. Gao, M. Z, et al., Real-time Evolution and Connectivity of Mined Crack Network, Journal of China Coal Society, 37 (2012), 9, pp. 1535-1540
  4. Gao, M. Z, et al., Relevance between Abutment Pressure and Fractal Dimension of Crack Network Induced by Mining, International Journal of Mining Science & Technology, 23(2013), 6, pp. 925-930
  5. Gilman, A., R. Beckie, Flow of Coal-Bed Methane to a Gallery, Transport in Porous Media, 41(2000), 1, pp. 1-16
  6. Xie, J., et al., Coal Permeability Model on the Effect of Gas Extraction within Effective Influence Zone, Geomechanics and Geophysics for Geo-Energy and Geo-Resources, 1(2015), 1-2, pp. 15-27
  7. Schatzel, S. J., et al., An Analysis of Reservoir Conditions and Responses in Longwall Panel Overburden during Mining and Its Effect on Gob Gas Well Performance, Engineering Geology, 127(2012), 3, pp. 65-74
  8. Ju, Y., et al., Fractal Model and Lattice Boltzmann Method for Characterization of Non-Darcy Flow in Rough Fractures, Science Report, 7(2017), pp. 41380
  9. Jin, W., et al., Elliptical Fracture Network Modeling with Validation in Datong Mine, China, Environmental Earth Sciences, 73(2015), 11, pp. 1-13
  10. Liu, H., et al., The Elimination of Coal and Gas Outburst Disasters by Long Distance Lower Protective Seam Mining Combined with Stress-Relief Gas Extraction in the Huaibei Coal Mine Area, Journal of Natural Gas Science & Engineering, 27(2015), pp. 346-353
  11. Whitworth, K. R., Induced Changes in Permeability of Coal Measure Strata as an Indicator of the Mechanics of Rock Deformation Above a Longwall Coal Face, Developments in Geotechnical Engineering, 32(1981), pp. 18-24
  12. Karacan, C. Ö., Prediction of Porosity and Permeability of Caved Zone in Longwall Gobs, Transport in Porous Media, 82(2010), 2, pp. 413-439
  13. Zhang, Y., et al., Experiment Research on Changes of Coal Pressure after Mining Protective Coal Seam by Field Test, Proceedings of the Seventh International Conference on Measuring Technology & Mechatronics Automation, Beijing, China, 2015, pp. 473-476.
  14. Zhang, Z., et al., Mining-Induced Coal Permeability Change Under Different Mining Layouts, Rock Mechanics & Rock Engineering, 49(2016), 9, pp. 1-16
  15. Gao, M. Z., et al., Field Experiments on Fracture Evolution and Correlations between Connectivity and Abutment Pressure under Top Coal Caving Conditions, International Journal of Rock Mechanics and Mining Sciences, 111(2018), 3, pp. 84-93
  16. Xie, J., et al., A New Theoretical Model for Guiding the Gas Extraction in Coal Mines, Thermal Science, 21(2017), suppl. 1, pp. 293-300
  17. Jafari, A., T. Babadagli, Relationship between Percolation-Fractal Properties and Permeability of 2-D Fracture Networks, International Journal of Rock Mechanics & Mining Sciences, 60(2013), 6, pp. 353-362
  18. Xie, H. P., et al., Mining-Induced Mechanical Behavior in Coal Seams under Different Mining Layouts (in Chinese), Journal of China Coal Society 36(2011), 7, pp. 1067-1074
  19. Chen, J., et al., Determining Three Demensional Connectivity of Rockmass Discontinuity by Projection (in Chinese), Chinese Journal of Rock Mechanics and Engineering, 24(2005), 15, pp. 2617-2621

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