Abstract
The reasonable selection of the protective coal mining (PCS) thickness and the quantitative relationship between the mining thickness and the interlayer spacing directly affect the performance of the pressure relief gas drainage and the safe mining of the PCS. Thus, the evolution of the protected coal seam (PDCS) permeability under the different PCS mining thickness in Huainan and Hancheng mining area is simulated by using the stress-damage-seepage coupling model. The results show that the PDCS permeability presents an S type increasing with the increase of the mining thickness. The logistic function formula for quantitative analysis of the relationship between the PCS mining thickness and PDCS permeability is given. The optimal mining thickness of the PCS in Huainan and Hancheng mining area is 1.73 m and 0.96 m, respectively, and the reasonable mining thickness range is 0.87–4.06 and 0.68–1.32 m. Based on the numerical simulation, the quantitative curve between the mining thickness and the interlayer spacing of the upper and lower PCS mining in Hancheng and Huainan mining area is presented. Finally, the reliability of the numerical simulation is verified by the filed measurement of the fracture development in the roof and the permeability of the PDCS.
Similar content being viewed by others
References
Jiang JY, Cheng YP, Wang L, Li W, Wang L (2011) Petrographic and geochemical effects of sill intrusions on coal and their implications for gas outbursts in the Wolonghu Mine, Huaibei coalfield China. Int J Coal Geol 88(1):55–66
Jiang J, Cheng Y, Zhang P, Jin K, Cui J, Du H (2015) CBM drainage engineering challenges and the technology of mining protective coal seam in the Dalong Mine, Tiefa Basin, China. J Nat Gas Sci Eng 24:412–424
Karacan CÖ, Goodman G (2009) Hydraulic conductivity changes and influencing factors in longwall overburden determined by slug tests in gob gas ventholes. Int J Rock Mech Min Sci 46(7):1162–1174
Karacan CÖ, Ruiz FA, Cotè M, Phipps S (2011) Coal mine methane: a review of capture and utilization practices with benefits to mining safety and to greenhouse gas reduction. Int J Coal Geol 86(2):121–156
Liu HB, Cheng YP, Song JC, Shang ZJ (2010) The change and distribution law of outburst coal seam permeability induced by drilling an extra-thin protective coal seam. J China Coal Soc 35(3):411–416
Liu SJ, Lin BQ, Gao J, Hao ZY, Li QG, Meng J (2011) Similar simulation of fracture deformation in overlying coal and rock in far distance lower protective layer mining. J Min Saf Eng 28(1):51–55
Lu T, Yu H, Zhou T, Mao J, Guo B (2009) Improvement of methane drainage in high gassy coal seam using waterjet technique. Int J Coal Geol 79(1):40–48
Palchik V (2003) Formation of fractured zones in overburden due to longwall mining. Environ Geol 44(1):28–38
Palchik V (2010) Experimental investigation of apertures of mining-induced horizontal fractures. Int J Rock Mech Min Sci 47(3):502–508
Szlązak N, Obracaj D, Swolkień J (2014) Methane drainage from roof strata using an overlying drainage gallery. Int J Coal Geol 136:99–115
Wang F, Ren T, Tu S, Hungerford F, Aziz N (2012) Implementation of underground longhole directional drilling technology for greenhouse gas mitigation in Chinese coal mines. Int J Greenh Gas Control 11:290–303
Xie H, Gao F, Ju Y, Gao M, Zhang R, Gao Y, Liu J, Xie L (2015) Quantitative definition and investigation of deep mining. J China Coal Soc 40(1):1–10
Yang TH, Xu T, Liu HY, Tang CA, Shi BM, Yu QX (2011a) Stress–damage–flow coupling model and its application to pressure relief coal bed methane in deep coal seam. Int J Coal Geol 86(4):357–366
Yang W, Lin BQ, Qu YA, Zhao S, Zhai C, Jia LL, Zhao WQ (2011b) Mechanism of strata deformation under protective seam and its application for relieved methane control. Int J Coal Geol 85(3–4):300–306
Yang W, Lin BQ, Yan Q, Zhai C (2014) Stress redistribution of longwall mining stope and gas control of multi-layer coal seams. Int J Rock Mech Min Sci 72:8–15
Yavuz H (2004) An estimation method for cover pressure re-establishment distance and pressure distribution in the goaf of longwall coal mines. Int J Rock Mech Min Sci 41(2):193–205
Yuan L, Guo H, Shen BT, Qu QD, Xue JH (2011) Circular overlying zone at longwall panel for efficient methane capture of mutiple coal seams with low permeability. J China Coal Soc 36(3):357–365
Zhang C, Tu S, Bai Q, Yang G, Zhang L (2015) Evaluating pressure-relief mining performances based on surface gas venthole extraction data in longwall coal mines. J Natural Gas Sc Eng 24:431–440
Zhang C, Tu S, Zhang L, Bai Q, Yuan Y, Wang F (2016a) A methodology for determining the evolution law of gob permeability and its distributions in longwall coal mines. J Geophys Eng 13(2):181–193
Zhang C, Tu S, Zhang L, Wang F, Bai Q, Tu H (2016b) The numerical simulation of permeability rules in protective seam mining. Int J Oil Gas Coal Technol 13(3):243–259
Zhang C, Tu S, Chen M, Zhang L (2017) Pressure-relief and methane production performance of pressure relief gas extraction technology in the longwall mining. J Geophys Eng 14(1):77–89
Acknowledgements
Financial support for this work was supported by Beijing Natural Science Foundation (8184082), the National Natural Science Foundation of China (Nos. 51874281 and 51704274), the Jiangsu Planned Projects for Postdoctoral Research Funds (1601002B) and the Yue Qi Distinguished Scholar Project, China University of Mining & Technology, Beijing.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Zhang, C., Tu, S. & Zhang, L. Mining Thickness Determination of Upper and Lower Protective Coal Seam in Pressure Relief Mining. Geotech Geol Eng 37, 1813–1827 (2019). https://doi.org/10.1007/s10706-018-0724-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10706-018-0724-3