Geomechanics and Engineering

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An analytical approach to estimate the mechanical state of roof strata in underground longwall mining

  • Zhang, Jie (College of Safety and Environmental Engineering, Shandong University of Science and Technology) ;
  • Zhang, Yansong (College of Safety and Environmental Engineering, Shandong University of Science and Technology) ;
  • Du, Wenzhou (College of Safety and Environmental Engineering, Shandong University of Science and Technology) ;
  • Wang, Houwang (College of Safety and Environmental Engineering, Shandong University of Science and Technology) ;
  • Serati, Mehdi (School of Civil Engineering, The University of Queensland)
  • Received : 2021.05.13
  • Accepted : 2021.09.28
  • Published : 2021.10.10
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Abstract

The movement and collapse of roof strata in underground longwall mining is a key trigger factor for the occurrence of dynamic disasters. An accuracy estimation of roof strata mechanical state is critical for the prediction and control of dynamic disaster, such as coal burst and coal-and-gas outburst. An analytical approach is proposed in this work to estimate the mechanical state of roof strata in underground longwall mining. To do so, the unit width of roof strata is considered as a beam structure. A system of 4 simulations differential equations is proposed with 4 local slope data as input parameters to derive the mechanical expression of suspending roof strata. A differential evolution algorithm is further adapted to solve the equation system. In addition, a set of verification tests is carried out to showcase the feasibility and robustness of the proposed method. The results show that the average relative errors of 10 independent tests reach a high accuracy, which is less than 1% for the strata mechanical state control parameters. By using the estimated results, the slope, bending moment and shear force of suspending strata are derived. Moreover, the slope data sampling strategy is also devised. The parameters bound determination method is also proposed to ensure the calculation convergence. The local slope based analytical method proposed in this paper is a feasible approach to estimate the mechanical state of suspended roof strata before first weighting.

Keywords

Acknowledgement

The research described in this paper was financially supported by the National Natural Science Foundation of China (No. 52104201) and the Natural Science Foundation of Shandong Province (No. ZR2020QE131).

References

  1. Boothukuri V.R., Bhattacharjee R.M., Panigrahi D.C. and Benerjee G. (2019), "Impact of geotechnical factors on strata behavior in longwall panels of Godavari Valley coal field-a case study", Int. J. Min. Sci. Technol., 29(02), 335-341. https://doi.org/10.1016/j.ijmst.2018.06.01.
  2. Brady, B.H.G. and Brown, E.T. (2012), Rock Mechanics: For Underground Mining, Springer, Dordrecht, The Netherlands.
  3. Cetin, M., Brooks, R.M. and Udo-Inyang, P. (2012), "An innovative design methodology of pavement design by limiting surface deflection", Int. J. Recent Res. Appl. Stud., 13(2), 607-610.
  4. Carla, T., Intrieri, E., Farina, P. and Casagli, N. (2017), "A new method to identify impending failure in rock slopes", Int. J. Rock Mech. Min. Sci., 93, 76-78. https://doi.org/10.1016/j.ijrmms.2017.01.015.
  5. Diederichs, M.S., and Kaiser, P.K. (1999), "Stability of large excavations in laminated hard rock masses: The voussoir analogue revisited", Int. J. Rock Mech. Min. Sci., 36(1), 97-117. https://doi.org/10.1016/S0148-9062(98)00180-6.
  6. Evans, W.H. (1941), "The strength of undermined strata", Trans. Inst. Min. Metall., 50, 475-532.
  7. Galvin, J.M. (2016), Ground Engineering - Principles and Practices for Underground Coal Mining, Springer Nature, Switzerland.
  8. Gui, H.R., Tong, S.J., Qiu, W.Z. and Lin, M.L. (2018), "Research on preventive technologies for bed-separation water hazard in China coal mines", Appl. Water Sci., 8(1), 375. https://doi.org/10.1007/s13201-018-0667-0
  9. Guo, L., Zhang, L., Song, Y., Zhao, L., and Zhao, Q. (2019), "Design and implementation of a novel tilt sensor based on the principle of variable reluctance", Sensors, 19(23). https://doi.org/10.3390/s19235228.
  10. Heijden, A.M. (2008), W.T. Koiter's Elastic Stability of Solids and Structures, Cambridge University Press, New York, U.S.A.
  11. Hesser, J., Kaiser, D., Schmitz, H. and Spies, T. (2015), "Measurements of acoustic emission and deformation in a repository of nuclear waste in salt rock", Eng. Geol. Soc. Territory, 6(1), 551-554. https://doi.org/10.1007/978-3-319-09060-399.
  12. Hou, C., Zhu, W., Yan, B., Guan, K. and Niu, L. (2019), "Analytical and experimental study of cemented backfill and pillar interactions", Int. J. Geomech., 19(8). https://doi.org/10.1061/(ASCE)GM.1943-5622.0001441
  13. Jiang, L., Mitri, H.S., Ma, N. and Zhao, X. (2016), "Effect of foundation rigidity on stratified roadway roof stability in underground coal mines", Arab. J. Geosci., 9(1), 1-12. https://doi.org/10.1007/s12517-015-2033-y.
  14. Ji, S., Zhang, J., Pan, R. and Karlovsek, J. (2020), "Local acceleration monitoring and its application in physical modelling of underground mining", Int. J. Rock Mech. Min. Sci., 128(6), 104282. https://doi.org/10.1016/j.ijrmms.2020.104282.
  15. Ji, S., He, H. and Karlovsek, J. (2021), "Application of superposition method to study the mechanical behaviour of overlying strata in longwall mining", Int. J. Rock Mech. Min. Sci., 146, 104874. https://doi.org/10.1016/j.ijrmms.2021.104874
  16. Keykhosropour, L., and Lemnitzer, A. (2018), "Comparison of measurements and limit state solutions for soil pressures on deep flexible underground structures", Geotech. Sp. Publ., 297(3), 169-178. https://doi.org/10.1061/9780784481608.017.
  17. Kong, X., Wang, E., He, X., Li, D. and Liu, Q. (2017), "Time-varying multifractal of acoustic emission about coal samples subjected to uniaxial compression", Chaos Solitons Fractals, 103(1), 571-577. https://doi.org/10.1016/j.chaos.2017.07.015.
  18. Konicek P., Schreiber J., and Nazarova L. (2019), "Volumetric changes in the focal areas of seismic events corresponding to destress blasting", Int. J. Min. Sci. Technol., 29(4), 541-547. https://doi.org/10.1016/j.ijmst.2019.06.004.
  19. Li, L., Li, J., Sun, D. and Gong, W. (2017), "Semi-analytical approach for time-dependent load-settlement response of a jacked pile in clay strata", Can. Geotech. J., 54(12), 1682-1692. https://doi.org/10.1139/cgj-2016-0561.
  20. Luczak, S. and Ekwinska, M. (2021), "Electric-contact tilt sensors: a review", Sensors, 21(4). https://doi.org/10.3390/s21041097
  21. Mirenkov, V.E., (2017), "Interaction between enclosing rocks and roof support during stoping", J. Min. Sci., 53(5), 811-817. https://doi.org/10.1134/S1062739117052813.
  22. Mojtaba, M., Liu, H., Andrew, C., Sevda, D. and Daisuke, F. (2018), "An overview on advances in computational fracture mechanics of rock", Geosyst. Eng., 3(12). https://doi.org/10.1080/12269328.2018.1448006.
  23. Mohamed, A.W., Sabry, H.Z., and Khorshid, M. (2012), "An alternative differential evolution algorithm for global optimization", J. Adv. Res., 3(2), 149-165. https://doi.org/10.1016/j.jare.2011.06.004.
  24. Ning J., Wang J., Tan Y., and Qiang X. (2020), "Mechanical mechanism of overlying strata breaking and development of fractured zone during close-distance coal seam group mining", Int. J. Min. Sci. Technol., 30(2), 207-215. https://doi.org/10.1016/j.ijmst.2019.03.001
  25. Omidi, J. and Mazaheri, K. (2020), "Differential evolution algorithm for performance optimization of the micro plasma actuator as a microelectromechanical system", Sci. Reports, 10(1), 18865. https://doi.org/10.1038/s41598-020-75419-5
  26. Pan, Y, Gu, S. and Qi, Y. (2013), "Analytic solution of tight roof's bending moment, deflection and shear force under advanced super charger load and supporting resistance before first weighting", Chin. J. Rock Mech. Eng., 32(8), 1545-1553.
  27. Peng, S.S. (2017), Advances in Coal Mine Ground Control, Woodhead Publishing, Duxford, England, U.K.
  28. Rout, U. K., Sahu, R. K., and Panda, S. (2013), "Design and analysis of differential evolution algorithm based automatic generation control for interconnected power system", Ain Shams Eng. J., 4(3), 409-421. https://doi.org/10.1016/j.asej.2012.10.010.
  29. Sellers, E.J., Kataka, M.O. and Linzer, L.M. (2003), "Source parameters of acoustic emission events and scaling with mining-induced seismicity", J. Geophys. Res. Solid Earth, 108(B9), 24, 003. https://doi.org/10.1029/2001JB000670.
  30. Song, Z. (1988), Utility mine Pressure and Control, China University of Mining and Technology Press, Xu Zhou, China.
  31. Song, D., Wang, E., Li, Z., Qiu, L. and Xu, Z. (2017), "EMR: An effective method for monitoring and warning of rock burst hazard", Geomech. Eng., 12(1), 53-69. https://doi.org/10.12989/gae.2017.12.1.053.
  32. Sun, J., Wang, L. and Hou, H. (2012), "Application of micro-seismic monitoring technology in mining engineering", Int. J. Min. Sci. Technol., 22(1), 79-83. https://doi.org/10.1016/j.ijmst.2011.06.007.
  33. Stolecki, L. and Grzebyk, W. (2021), "The velocity of roof deflection as an indicator of underground workings stability - Case study from Polish deep copper mines", Int. J. Rock Mech. Min. Sci., 143, 104717. https://doi.org/10.1016/j.ijrmms.2021.104717.
  34. Timoshenko, S.P., Gere, J.M. and Prager, W. (1962), "Theory of elastic Stability, second edition", J. Appl. Mech., 29(1), 220-221. https://doi.org/10.1115/1.3636481.
  35. Vecchia, G.D., Bellis, M.L.D. and Pandolfi, A. (2016), "A multiscale microstructural model of damage and permeability in fractured solids", Proc. Eng., 158, 21-26. https://doi.org/10.1016/j.proeng.2016.08.399.
  36. Whittaker, B.N. and Reddish, D. J. (1989), Subsidence: Occurrence, Prediction and Control, Elsevier Science Publishers B.V, The Netherlands.
  37. Will, R., Smith, V., Leetaru, H. E., Freiburg, J. T., and Lee, D. W. (2014), "Microseismic monitoring, event occurrence, and the relationship to subsurface geology", Energy Procedia, 63, 4424-4436. https://doi.org/10.1016/j.egypro.2014.11.478.
  38. Yu, B. (2016), "Behaviors of overlying strata in extra-thick coal seams using top-coal caving method", J. Rock Mech. Geotech. Eng., 8(2), 238-247. https://doi.org/10.1016/j.jrmge.2015.11.006.
  39. Yu, Y., Ou, J., Zhang, J, Zhang, C. and. Li, L. (2009), "Development of wireless MEMS inclination sensor system for swing monitoring of large-scale hook structures", IEEE T. Industr. Electronics, 56(4), 1072-1078. https://doi.org/10.1109/TIE.2009.2012469.
  40. Zhang J., Yang W., Lin B., Zhang J. and Wang M. (2019), "Strata movement and stress evolution when mining two overlapping panels affected by hard stratum", Int. J. Min. Sci. Technol., 29(5), 691-699. https://doi.org/10.1016/j.ijmst.2019.07.001
  41. Zhang, K., Ji, S., Zhang, Y., Zhang, J. and Pan, R. (2018), "MEMS inertial sensor for strata stability monitoring in underground mining: an experimental study", Shock Vib., (6), 1-8. https://doi.org/10.1155/2018/4895862.
  42. Zou, X., Thiruvenkatanathan, P. and Seshia, A. A. (2014), "A high-resolution micro-electro-mechanical resonant tilt sensor", Sensors Actuators A Phys., 220, 168-177. https://doi.org/10.1016/j.sna.2014.10.004.