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KSCE Journal of Civil Engineering

, Volume 23, Issue 9, pp 3793–3806 | Cite as

Stress Distribution and Failure Characteristics for Workface Floor of a Tilted Coal Seam

  • Jian SunEmail author
  • Lianguo Wang
  • Guangming Zhao
Geotechnical Engineering
  • 27 Downloads

Abstract

A mechanical model for the tilted workface floor along the tilted direction of coal seam was proposed. Stress expressions of an arbitrary point inside the tilted workface floor were deduced. Calculation formula for the maximum failure depth of the lateral floor strata of the tilted workface was also deduced. Based on the Mohr-Coulomb yield criterion, the tilted workface floor’s stress distribution, and failure depth and shape were simulated by using FLAC3D software for different coal seam’s dip angles, buried depths, and workface widths. Results show that the concentration coefficient, the peak value and the distance between the peak position of the lateral abutment pressure and the roadway on both sides of the tilted workface decreases with the increases in coal seam’s dip angle. The vertical stress isoclines present a “spoon-shaped” distribution along the tilted direction of workface. Both sides of the workface form “bubble-shaped” distribution shear stress and its peak value increases first and then decreases with the increases in coal seam’s dip angle and reaches maximum at 30°–35°. The tilted workface floor’s plastic failure zone presents a “spoon-shaped” distribution along the tilted direction of workface, which is large on the lower side and small on the upper side. The plastic zone’s failure depth increases first and then decreases with the increases in the dip angle of coal seam and reaches maximum at 30°.

Keywords

tilted coal seam workface floor stress distribution failure characteristics failure depth failure shape 

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Notes

Acknowledgements

This work was supported by the Major Research Funding Project of Natural Science of Anhui Province University (No. KJ2018ZD010), the National Natural Science Foundation of China (No. 51404013), and the Open Projects of State Key Laboratory for Geomechanics and Deep Underground Engineering at the China University of Mining and Technology (No. SKLGDUEK1212).

References

  1. Chen, J. G., Xiong, Z. Q., Li, H., Yu, Y., Nie, B. S., Wang, S. D., and Wang, X. L. (2016). “Failure characteristics of floor under predssure inclined and extra thick coal seam in full-mechanized top coal caving faces.” Chinese Journal of Rock Mechanics and Engineering, Vol. 35, No. S1, pp. 3018–3023, DOI:  https://doi.org/10.13722/j.cnki.jrme.2014.1450.Google Scholar
  2. Cheng, Y. H., Bai, J. C., Ma, Y. K., Sun, J., Liang, Y. P., and Jiang, F. X. (2015). “Control mechanism of rock burst in the floor of roadway driven along next goaf in thick coal seam with large obliquity angle in deep well.” Shock and Vibration, Vol. 2015, pp. 1–10, DOI:  https://doi.org/10.1155/2015/750807.Google Scholar
  3. Feng, Q. and Jiang, B. S. (2015). “Analytic solution for stress and deformation of stope floor based on integral transform.” Rock and Solid Mechanics, Vol. 36, No. 12, pp. 3482–3487, DOI:  https://doi.org/10.16285/j.rsm.2015.12.019.Google Scholar
  4. Jiang, Y. D., Lv, Y. K., Zhao, Y. X., and Zhang, D. Y. (2011). “Similar simulation test for breakage law of working face floor in coal mining above aquifer.” Chinese Journal of Rock Mechanics and Engineering, Vol. 30, No. 8, pp. 1571–1577.Google Scholar
  5. Li, J. H., Xu, Y. C., Xie, X. F., Yao, Y. L., and Gao, Y B. (2015). “Influence of mining height on coal seam floor failure depth.” Journal of China Coal Society, Vol. 40, No. S2, pp. 303–310, DOI:  https://doi.org/10.13225/j.cnki.jccs.2015.0033.Google Scholar
  6. Liu, X. J., Li, X. M., and Pan, W. D. (2016). “Analysis on the floor stress distribution and roadway position in the close distance coal seams.” Arabian Journal of Geosciences, Vol. 9, No. 2, pp. 83, DOI:  https://doi.org/10.1007/s12517-015-2035-9.CrossRefGoogle Scholar
  7. Liu, S. L., Liu, W. T., Huo, Z. C., and Song, W. C. (2019). “Early warning information evolution characteristics of water inrush from floor in underground coal mining.” Arabian Journal of Geosciences, Vol. 12, No. 2, pp. 30, DOI:  https://doi.org/10.1007/s12517-018-4181-3.CrossRefGoogle Scholar
  8. Liu, W. T., Liu, S. L., and Ji, B. J. (2015). “Sensitivity analysis of controlling factors on failure depth of floor based on orthogonal experiment.” Journal of China Coal Society, Vol. 40, No. 9, pp. 1995–2001, DOI:  https://doi.org/10.13225/j.cnki.jccs.2014.1682.Google Scholar
  9. Liu, S. L., Liu, W. T., and Shen, J. J. (2017). “Stress evolution law and failure characteristics of mining floor rock mass above confined water.” KSCE Journal of Civil Engineering, KSCE, Vol. 21, No. 7, pp. 2665–2672, DOI:  https://doi.org/10.1007/s12205-017-1578-6.CrossRefGoogle Scholar
  10. Liu, W. T., Mu, D. R., Xie, X. X., Yang, L., and Wang, D. H. (2018). “Sensitivity analysis of the main factors controlling floor failure depth and a risk evaluation of floor water inrush for an inclined coal seam.” Mine Water and the Environment, Vol. 37, No. 3, pp. 636–648, DOI:  https://doi.org/10.1007/s10230-017-0497-6.CrossRefGoogle Scholar
  11. Liu, W. T., Mu, D. R., Yang, L., Li, L. Y., and Shi, C. H. (2017). “Calculation method and main factor sensitivity analysis of inclined coal floor damage depth.” Journal of China Coal Society, Vol. 42, No. 4, pp. 849–859, DOI:  https://doi.org/10.13225/j.cnki.jccs.2016.0863.Google Scholar
  12. Lu, Y. L. and Wang, L. G. (2015). “Numerical simulation of mining-induced fracture evolution and water flow in coal seam floor above a confined aquifer.” Computers and Geotechnics, Vol. 67, pp. 157–171, DOI:  https://doi.org/10.1016/j.compgeo.2015.03.007.CrossRefGoogle Scholar
  13. Lu, H. F. and Yao, D. X. (2014). “Stress distribution and failure depths of layered rock mass of mining floor.” Chinese Journal of Rock Mechanics and Engineering, Vol. 33, No. 10, pp. 2030–2039, DOI:  https://doi.org/10.13722/j.cnki.jrme.2014.10.039.Google Scholar
  14. Meng, X. R., Xu, C. H., Gao, Z. N., and Wang, X. Q. (2010). “Stress distribution and damage mechanism of mining floor.” Journal of China Coal Society, Vol. 35, No. 11, pp. 1832–1836.Google Scholar
  15. Sun, J. (2011). Failure characteristics and water-inrush mechanism of an inclined coal seam floor. PhD Thesis, China University of Mining and Technology, Xuzhou, China.Google Scholar
  16. Sun, J. and Wang, L. G. (2014). “Instability mechanics criterion of inclined water-resisting key strata in coal seam floor.” Journal of China Coal Society, Vol. 39, No. 11, pp. 2276–2285, DOI:  https://doi.org/10.13225/j.cnki.jccs.2013.1354.Google Scholar
  17. Sun, J., Wang, L. G., Tang, F. R., Shen, Y. F., and Gong, S. L. (2011). “Microseismic monitoring on the failure characteristics of an inclined coal seam floor.” Rock and Solid Mechanics, Vol. 32, No. 5, pp. 1589–1595.Google Scholar
  18. Tan, Y. L., Zhao, T. B., and Xiao, Y. X. (2010). “In situ investigations of failure zone of floor strata in mining close distance coal seams.” International Journal of Rock Mechanics and Mining Sciences, Vol. 47, No. 5, pp. 865–870, DOI:  https://doi.org/10.1016/j.ijrmms.2009.12.016.CrossRefGoogle Scholar
  19. Timoshenko, S. P. and Woinowsky-Krieger, S. W. (1959). Theory of plates and shells. McGraw-Hill Press, New York, USA.zbMATHGoogle Scholar
  20. Wang, L. G., Han, M., Wang, Z. S., and Ou, S. B. (2013). “Stress distribution and damage law of mining floor.” Journal of Mining and Safety Engineering, Vol. 30, No. 3, pp. 317–322.Google Scholar
  21. Xiao, F. K., Duan, L. Q., and Ge, Z. H. (2010). “Laws of floor breaking in coal mining face and gas extraction application.” Journal of China Coal Society, Vol. 35, No. 3, pp. 417–419.Google Scholar
  22. Yin, H. Y., Liliana, L., Wei, J. C., Guo, J. B., Li, Z. J., and Guan, Y. Z. (2016). “In situ dynamic monitoring of stress revolution with time and space under coal seam floor during longwall mining.” Environmental Earth Sciences, Vol. 75, No. 18, pp. 1249, DOI:  https://doi.org/10.1007/s12665-016-6071-x.CrossRefGoogle Scholar
  23. Yin, H. Y., Sang, S. Z., Xie, D. L., Zhao, H., Li, S. J., Li, H. S., and Zhuang, X. H. (2019). “A numerical simulation technique to study fault activation characteristics during mining between fault bundles.” Environmental Earth Sciences, Vol. 78, No. 5, pp. 148, DOI:  https://doi.org/10.1007/s12665-019-8142-2.CrossRefGoogle Scholar
  24. Zhang, S. C., Guo, W. J., and Li, Y. Y. (2017). “Experimental simulation of water-inrush disaster from the floor of mine and its mechanism investigation.” Arabian Journal of Geosciences, Vol. 10, No. 22, p. 503, DOI:  https://doi.org/10.1007/s12517-017-3287-3.CrossRefGoogle Scholar
  25. Zhang, R., Jiang, Z. Q., Li, X. H., Chao, H. D., and Sun, Q. (2013). “Study on the failure depth of thick seam floor in deep mining.” Journal of China Coal Society, Vol. 38, No. 1, pp. 67–72.Google Scholar
  26. Zhang, B. L. and Meng, Z. B. (2019). “Experimental study on floor failure of coal mining above confined water.” Arabian Journal of Geosciences, Vol. 12, No. 4, pp. 114, DOI:  https://doi.org/10.1007/s12517-019-4250-2.MathSciNetCrossRefGoogle Scholar
  27. Zhang, W., Zhang, D. S., Chen, J. B., Wang, X. F., and Xu, M. T. (2012). “Determining the optimum gateway location for extremely close coal seams.” Journal of China University of Mining and Technology, Vol. 41, No. 2, pp. 182–188.Google Scholar
  28. Zhang, J. C., Zhang, Y. Z., and Liu, T. Q. (1997). Rock mass permeability and coal mine water inrush. Geological Publishing House, Beijing, China.Google Scholar
  29. Zhao, Q. B., Zhao, X. N., Wu, Q., Liu, C. W., and Wang, X. L. (2015). “Water burst mechanism of ‘divided period and section burst’ at deep coal seam floor in North China type coalfield mining area.” Journal of China Coal Society, Vol. 40, No. 7, pp. 1601–1607, DOI:  https://doi.org/10.13225/j.cnki.jccs.2015.0358.Google Scholar
  30. Zhu, S. Y., Jiang, Z. Q., Zhou, K. J., Peng, G. Q., and Yang, C. W. (2014). “The characteristics of deformation and failure of coal seam floor due to mining in Xinmi coal field in China.” Bulletin of Engineering Geology and the Environment, Vol. 73, No. 4, pp. 1151–1163, DOI:  https://doi.org/10.1007/s10064-014-0612-x.CrossRefGoogle Scholar

Copyright information

© Korean Society of Civil Engineers 2019

Authors and Affiliations

  1. 1.School of Energy and SafetyAnhui University of Science and TechnologyHuainanChina
  2. 2.State Key Laboratory For Geomechanics and Deep Undergroud EngineeringChina University of Mining and TechnologyXuzhouChina

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