Journal of Central South University

, Volume 25, Issue 2, pp 448–460 | Cite as

Prediction of upper limit position of bedding separation overlying a coal roadway within an extra-thick coal seam

  • Hong Yan (严红)
  • Ji-xiong Zhang (张吉雄)
  • Lin-yue Li (李林玥)
  • Rui-min Feng (冯锐敏)
  • Tian-tong Li (李天彤)
Article
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Abstract

Failure of the surrounding rock around a roadway induced by roof separation is one major type of underground roof-fall accidents. This failure can especially be commonly-seen in a bottom-driven roadway within an extra-thick coal seam (“bottom-driven roadway” is used throughout for ease of reference), containing weak partings in their roof coal seams. To determine the upper limit position of the roof interlayer separation is the primary premise for roof control. In this study, a mechanical model for predicting the interlayer separation overlying a bottom-driven roadway within an extra-thick coal seam was established and used to deduce the vertical stress, and length, of the elastic, and plastic zones in the rock strata above the wall of the roadway as well as the formulae for calculating the deflection in different regions of rock strata under bearing stress. Also, an approach was proposed, calculating the stratum load, deflection, and limiting span of the upper limit position of the interlayer separation in a thick coal seam. Based on the key strata control theory and its influence of bedding separation, a set of methods judging the upper limit position of the roof interlayer separation were constructed. In addition, the theoretical prediction and field monitoring for the upper limit position of interlayer separation were conducted in a typical roadway. The results obtained by these two methods are consistent, indicating that the methods proposed are conducive to improving roof control in a thick coal seam.

Key words

extra-thick coal seam bedding separation coal roadway roof fall mechanical model 

特厚煤层沿底巷道顶板层间离层上限位置的判定方法

摘要

顶板离层致巷道围岩失稳破坏是煤矿井下冒顶灾变事故的主要类型之一, 其中以顶板煤层中含夹矸层的特厚煤层沿底巷道尤为突出, 而开展此类巷道顶板稳定性控制进而防止冒顶事故重要前提是合理确定顶板层间离层的上限位置。 本文以特厚煤层沿底巷道为研究对象, 针对顶板层间离层的上限位置合理确定问题, 综合运用力学计算、 理论分析、 现场监测等方法, 建立了特厚煤层巷道顶板层间离层数学模型, 理论推导得出了巷道顶板岩层侧向塑性区和弹性区的垂直应力、 长度及不同区域挠度方程式。 提出了一套判定特厚煤层巷道顶板层间离层上限位置的方法, 并结合数学力学计算方法推导得出层间离层上限位置确定所需要满足的荷载条件、 极限跨度、 挠度条件及顶板关键层位置与离层位置范围的判定式。 选择典型特厚煤层巷道进行层间离层上限值的理论分析和现场监测, 计算推导和数据监测结果显示两者确定的离层上限位置是一致的, 证明了提出的判定方法是正确的。

关键词

特厚煤层 顶板离层 煤巷 冒顶 力学模型 

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References

  1. [1]
    UNAL E, OZKAN I, CAKMAKCI G. Modeling the behaviour of longwall coal mine gate roadways subjected to dynamic loading [J]. International Journal of Rock Mechanics and Mining Sciences, 2001, 38(2): 181–197.CrossRefGoogle Scholar
  2. [2]
    GONG Feng-qiang, LI Xi-bing, GAO Ke. Catastrophe progression method for stability classification of underground engineering surrounding rock [J]. Journal of Central South University: Science and Technology, 2008, 39(5): 1081–1087. (in Chinese)Google Scholar
  3. [3]
    LIU Hong-tao. Research on the design method of parameters supporting with bolt in coal road on the base of the anchored-clustered structure [D]. Beijing: China University of Mining and Technology (Beijing), 2007. (in Chinese)Google Scholar
  4. [4]
    JIANG Li-shuai, SAINOKI A, MITRI H S, MA Nian-jie, HAO Zhen. Influence of fracture-induced weakening on coal mine gateroad stability [J]. International Journal of Rock Mechanics and Mining Sciences, 2016, 88: 307–317.CrossRefGoogle Scholar
  5. [5]
    ZHANG Yuan, WAN Zhi-jun, GU Bin, ZHOU Chang-bing. An experimental investigation of transient heat transfer in surrounding rock mass of high geothermal roadway [J]. Thermal Science, 2016, 20(6): 2115–2124.CrossRefGoogle Scholar
  6. [6]
    KUSHWAHA A, SINGH SK, TEWARI S, SINHA A. Empirical approach for designing of support system in mechanized coal pillar mining [J]. International Journal of Rock Mechanics and Mining Sciences, 2010, 47(7): 1063–1078.CrossRefGoogle Scholar
  7. [7]
    PALEI S K, DAS S K. Sensitivity analysis of support safety factor for predicting the effects of contributing parameters on roof falls in underground coal mines [J]. International Journal of Coal Geology, 2008, 75(4): 241–247.CrossRefGoogle Scholar
  8. [8]
    XIE He-ping, WANG Jin-hua, SHEN Bao-hong, LIU Jian-zhong, JIANG Peng-fei, ZHOU Hong-wei, LIU Hong, WU Gang. New idea of coal mining: Scientific mining and sustainable mining capacity [J]. Journal of China Coal Society, 2012, 37(7): 1069–1079.Google Scholar
  9. [9]
    YAN Hong. Roof coal deformation mechanism and its control technology for roadways driving along the floor in ultra-thick coal seams [M]. Xuzhou: China University of Mining and Technology Press, 2017. (in Chinese)Google Scholar
  10. [10]
    KUMARA R, SINGHA A K, MISHRAB A K, SINGHA R. Underground mining of thick coal seams [J]. International Journal of Mining Science and Technology, 2015, 25(6): 885–896.CrossRefGoogle Scholar
  11. [11]
    WANG Qi. Research on control mechanism of surrounding rock failure in deep roadways with thick top-coal and contrast of new support systems [D]. Jinan: Shandong University, 2012. (in Chinese)Google Scholar
  12. [12]
    LI S C, WANG Q, WANG H T, JIANG B, WANG D C, ZHANG B, LI Y, RUAN G Q. Model test study on surrounding rock deformation and failure mechanisms of deep roadways with thick top coal [J]. Tunnelling and Underground Space Technology, 2015, 47: 52–63.CrossRefGoogle Scholar
  13. [13]
    HEBBLEWHITE B K, LU T. Geomechanical behavior of laminated, weak coal mine roof strata and the implications for a ground reinforcement strategy [J]. International Journal of Rock Mechanics and Mining Sciences, 2004, 41(1): 147–157.CrossRefGoogle Scholar
  14. [14]
    LU Ting-kai, LIU Yu-zhou, YU Hai-yong. Separation characteristics and mechanisms of laminated composite roof strata of longwall roadway [J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(sn1): 4663–4669.(in Chinese)Google Scholar
  15. [15]
    SHEN Bao-tang, POULSEN B. Investigation of overburden behaviour for grout injection to control mine subsidence [J]. International Journal of Mining Science and Technology, 2014, 24(3): 317–323.CrossRefGoogle Scholar
  16. [16]
    ZHANG Nong, YUAN Liang. Control principle of separating and broken roof rock strata in roadway [J]. Journal of Mining & Safety Engineering, 2006, 23(1): 34–38. (in Chinese)MathSciNetGoogle Scholar
  17. [17]
    SHEN Rong-xi, LIU Chang-you, WU Xiu-yi. Analysis and calculation on roof separation critical values of solid-coal roadway and gob-side roadway supported with bolts [J]. Journal of Sichuan University: Engineering Science Edition, 2007, 39(3): 19–23. (in Chinese)Google Scholar
  18. [18]
    GU Shuan-cheng, DING Xiao. Elastoplastic analysis of effect of bed separation on anchored mass loading in rock mass [J]. Rock and Soil Mechanics, 2013, 34(9): 2649–2654. (in Chinese)Google Scholar
  19. [19]
    JACOB O. The origin of roof falls in starting faces with the caving system [J]. International Journal of Rock Mechanics and Mining Sciences, 1964, 1(3): 313–314.CrossRefGoogle Scholar
  20. [20]
    ZHANG Guo-hua, LIANG Bing, ZHANG Hong-wei, ZHANG Xue-feng. Analysis of the roof separation in mining roadway and technical parameters determination of bolt combined supporting [J]. Journal of Chongqing University, 2010, 33(7): 135–140. (in Chinese)Google Scholar
  21. [21]
    HAN Chang-liang, ZHANG Nong, LI Gui-cheng, KAN Jia-guang. Bed separation mechanism under sequential roof collapse condition in a gob-side entry retaining [J]. Journal of China University of Mining & Technology, 2012, 41(6): 893–899. (in Chinese)Google Scholar
  22. [22]
    YU Tao, WANG Lai-gui. Mechanism of generation of overburden separation layer [J]. Journal of Liaoning Technical University, 2006, 25(1): 132–134. (in Chinese)MathSciNetGoogle Scholar
  23. [23]
    APEL D B. Using ground penetrating radar (GPR) in analyzing structural composition of mine roof [J]. Mining Engineering, 2005, 57: 56–60.Google Scholar
  24. [24]
    XIE Jian-lin, XU Jia-lin. Numerical and physical simulation of the detection of roof separation with ground penetrating radar [J]. Journal of Mining & Safety Engineering, 2017, 34(2): 317–322. (in Chinese)Google Scholar
  25. [25]
    ZHANG Bai-sheng, KANG Li-xun, YANG Shuang-suo. Numerical simulation on roof separation and deformation of full seam roadway with stratified roof and large section [J]. Journal of Mining & Safety Engineering, 2006, 23(3): 264–267. (in Chinese)Google Scholar
  26. [26]
    QIAN Ping-gao, XIE He-ping. Stability analysis of the damage rock strata within the roof and floor of the roadway [J]. Jiangsu Coal, 1992, 12(3): 12–15. (in Chinese)Google Scholar
  27. [27]
    WU De-yi, WEN Guang-kun, WANG Ai-lan. Discrimination of stability between layers of compound roof in deep mining [J]. Journal of Mining & Safety Engineering, 2011, 28(2): 252–257. (in Chinese)Google Scholar
  28. [28]
    KWON S, WILSON J W. Deformation mechanism of the underground excavations at the WIPP site [J]. Rock Mechanics and Rock Engineering, 1999, 32(2): 101–122.CrossRefGoogle Scholar
  29. [29]
    QIAN Ming-gao, MIAO Xie-xing, XU Jia-lin. Key strata theory in ground control [M]. Xuzhou: China University of Mining and Technology Press, 2003. (in Chinese)Google Scholar

Copyright information

© Central South University Press and Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.State Key Laboratory of Coal Resource and Safe MiningKey Laboratory of Deep Coal Resource Mining of Ministry of Education of China (China University of Mining & Technology)XuzhouChina
  2. 2.Guizhou Xinlian Blasting Engineering Group Co., LtdGuiyangChina
  3. 3.Department of Chemical and Petroleum EngineeringUniversity of CalgaryCalgaryCanada

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