Geomechanics and Engineering

  • 제24권6호
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  • Pages.519-529
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  • 2021
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  • 2005-307X(pISSN)
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  • 2092-6219(eISSN)
테크노프레스 (Techno-Press)
권호 표지
DOI QR코드

DOI QR Code

Deformation and permeability evolution of coal during axial stress cyclic loading and unloading: An experimental study

  • Wang, Kai (School of Emergency Management and Safety Engineering, China University of Mining & Technology (Beijing)) ;
  • Guo, Yangyang (School of Emergency Management and Safety Engineering, China University of Mining & Technology (Beijing)) ;
  • Xu, Hao (School of Emergency Management and Safety Engineering, China University of Mining & Technology (Beijing)) ;
  • Dong, Huzi (School of Emergency Management and Safety Engineering, China University of Mining & Technology (Beijing)) ;
  • Du, Feng (School of Emergency Management and Safety Engineering, China University of Mining & Technology (Beijing)) ;
  • Huang, Qiming (Key Laboratory of Mine Disaster Prevention and Control, Shandong University of Science & Technology)
  • 투고 : 2020.09.23
  • 심사 : 2021.03.15
  • 발행 : 2021.03.25
⟨ 이전 논문 다음 논문 ⟩

초록

In coal mining activities, the abutment stress of the coal has to undergo cyclic loading and unloading, affecting the strength and seepage characteristics of coal; additionally, it can cause dynamic disasters, posing a major challenge for the safety of coal mine production. To improve the understanding of the dynamic disaster mechanism of gas outburst and rock burst coupling, triaxial devices are applied to axial pressure cyclic loading-unloading tests under different axial stress peaks and different pore pressures. The existing empirical formula is use to perform a non-linear regression fitting on the relationship between stress and permeability, and the damage rate of permeability is introduced to analyze the change in permeability. The results show that the permeability curve obtained had "memory", and the peak stress was lower than the conventional loading path. The permeability curve and the volume strain curve show a clear symmetrical relationship, being the former in the form of a negative power function. Owing to the influence of irreversible deformation, the permeability difference and the damage of permeability mainly occur in the initial stage of loading-unloading, and both decrease as the number of cycles of loading-unloading increase. At the end of the first cycle and the second cycle, the permeability decreased in the range of 5.777 - 8.421 % and 4.311-8.713 %, respectively. The permeability decreases with an increase in the axial stress peak, and the damage rate shows the opposite trend. Under the same conditions, the permeability of methane is always lower than that of helium, and it shows a V-shape change trend with increasing methane pressures, and the permeability of the specimen was 3 MPa > 1 MPa > 2 MPa.

키워드

참고문헌

  1. Araei, A.A., Razeghi, H.R. and Ghalandarzadeh, A. (2012), "Effects of loading rate and initial stress state on stress-strain behavior of rock fill materials under monotonic and cyclicl loading conditions", Sci. Iranica, 19, 1220-1235. http://doi.org/10.1016/j.scient.2012.08.002.
  2. Chen, Y., Wang, S. and Wang, E. (2007), "Strength and elastic properties of sandstone under different testing conditions", J. Central South Univ., 2, 210-215. https://doi.org/10.1007/s11771-007-0042-z.
  3. Du, F. and Wang, K. (2019), "Unstable failure of gas-bearing coalrock combination bodies: Insights from physical experiments and numerical simulations", Pro. Safe. Environ. Protect., 129, 264-279. https://doi.org/10.1016/j.psep.2019.06.029.
  4. Du, F., Wang, K. and Guo, Y. (2020), "The mechanism of rockburst-outburst coupling disaster considering the coal-rock combination: An experiment study", Geomech. Eng., 22(3), 255-264. https://doi.org/10.12989/gae.2020.22.3.255.
  5. Elsworth, D., Wang, S. and Liu, J. (2012), "Mechanical behavior of methane infiltrated coal: The roles of gas desorption, stress level and loading rate", Rock Mech. Rock. Eng., 46(5), 945-958. https://doi.org/10.1007/s00603-012-0324-0.
  6. Elsworth, D., Wang, S. and Liu, J. (2013), "Permeability evolution during progressive deformation of intact coal and implications for instability in underground coal seams", Int. J. Rock Mech. Min. Sci., 58, 34-45. https://doi.org/ 10.1016/j.ijrmms.2012.09.005.
  7. Fan, L. and Liu, S. (2019), "Evaluation of permeability damage for stressed coal with cyclic loading: An experimental study", Int. J. Coal Geol., 216, 103338. https://doi.org/10.1016/j.coal.2019.103338.
  8. Fuenkajorn, K. and Phueakphum, D. (2010), "Effects of cyclic loading on mechanical properties of Maha Sarakham salt", Engg. Geol., 112, 43-52. https://doi.org/10.1016/j.enggeo.2010.01.002.
  9. Ghabezloo, S., Sulem, J. and Guedon, S. (2009), "Effective stress law for the permeability of a limestone", Int. J. Rock Mech. Min. Sci., 46(2), 297-306. https://doi.org/10.1016/j.ijrmms.2008.05.006.
  10. Gordon, R.B. and Davis, L.A. (1967), "Velocity and attenuation of seismic waves in imperfectly elastic rock", J. Geophys. Res., 73(12), 3917-3935. https://doi.org/10.1029/JB073i012p03917.
  11. Jafari, M.K., Pellet, F. and Boulon, M. (2004), "Experimental study of mechanical behaviour of rock joints under cyclic loading", Rock Mech. Rock. Eng., 37, 3-23. https://doi.org/10.1007/s00603-003-0001-4.
  12. Jiang, F., Wu, H. and Guo, J. (2021), "Experimental study of the damage evolution and radon exhalation characteristics of quasiuranium ore under constant amplitude cyclic loading and unloading", J. Radioanal. Nucl. Chem., 327(1), 373-384. https://doi.org/10.1007/S10967-020-07516-8.
  13. Jorat, M.E., Kreiter, S. and Moerz, T. (2013), "Strength and compressibility characteristics of peat stabilized with sand columns", Geomech. Eng., 5(6), 575-594. https://doi.org/10.12989/gae.2013.5.6.575.
  14. Kasani, H.A. and Chalaturnyk, R.J. (2017), "Influence of high pressure and temperature on the mechanical behavior and permeability of a fractured coal", Energies, 10, 854. https://doi.org/10.3390/en1007085.
  15. Lama, R. and Saghafi, A. (2002), Overview of gas outbursts and unusual emissions", Proceedings of the 2002 Coal Operators' Conference, Wollogong, Australia, February.
  16. Li, Y., Zhang, S. and Zhang, B. (2018), "Dilatation characteristics of the coals with outburst proneness under cyclic loading conditions and the relevant applications", Geomech. Eng., 14(5), 459-466. http://doi.org/10.12989/gae.2018.14.5.459.
  17. Liu, T. (2019), "Multifield coupling processes during gas drainage in deep fractured coal seam and its engineering response", Ph.D. Dissertation, China University of Mining and Technology, Beijing, China.
  18. Martin, C., Kaiser, P. and Christiansson, R. (2003), "Stress, instability and design of underground excavations", Int. J. Rock Mech. Min. Sci., 40, 1027-1047. https://doi.org/10.1016/S1365-1609(03)00110-2.
  19. Miao, S., Liu, Z. and Zhao, X. (2020), "Characteristics of energy dissipation and damage of Beishan granite under cyclic loading and unloading", Chin. J. Rock Mech. Eng., https://doi.org/10.13722/j.cnki.jrme.2020.0953.
  20. Mohamed, H.M. and Romao, X. (2018), "Performance analysis of a detailed FE modelling strategy to simulate the behaviour of masonry-infilled RC frames under cyclic loading", Earthq. Struct., 14(6), 551-565. http://doi.org/10.12989/eas.2018.14.6.551.
  21. Rudakov, D. and Sobolev, V. (2019), "A mathematical model of gas flow during coal outburst initiation", Int. J. Min. Sci., 29(5), 791-796. https://doi.org/10.1016/j.ijmst.2019.02.002.
  22. Russell, A., Shi, H. and Peter, M. (2004), "Influences of loading rate and preloading on the mechanical properties of dry elastoplastic granules under compression", Aichhe J., 1-14. https://doi.org/10.1002/aic.14572.
  23. Sobczyk, J. (2011), "The influence of sorption processes on gas stresses leading to the coal and gas outburst in the laboratory conditions", Fuel, 90(3), 1018-1023. https://doi.org/10.1016/j.fuel.2010.11.004.
  24. Sobczyk, J. (2014), "A comparison of the influence of adsorbed gases on gas stresses leading to coal and gas outburst", Fuel, 115, 288-294. https://doi.org/10.1016/j.fuel.2013.07.016.
  25. Taheri, A., Hamzah, N. and Dai, Q. (2017), "Degradation and improvement of mechanical properties of rock under triaxial compressive cyclic loading", Jap. Geotech. Soc. Sp. Pub., 5(2), 71-78. https://doi.org/10.3208/jgssp.v05.017.
  26. Terzaghi, K. (1943), Theoretical Soil Mechanics, John Wiley and Sons Inc., New York, U.S.A., 235-334.
  27. Wang, D., Wei, J. and Yin, G. (2012), "Investigation on change rule of permeability of coal containing gas under complex stress paths", Chin. J. Rock Mech. Eng., 31(2), 303-310. https://doi.org/1000-6915(2012)02-0303-08. https://doi.org/10.3969/j.issn.1000-6915.2012.02.009
  28. Wang, G., Guo, Y., Du, C.A., Sun, L., Liu, Z., Wang, Y. and Cao, J (2019b), "Experimental study on damage and gas migration characteristics of gas-bearing coal with different pore structures under sorption-sudden unloading of methane", Geofluids, 1-11. https://doi.org/10.1155/2019/7287438.
  29. Wang, G., Guo, Y., Wang, P., Li, W., Wu, M., Sun, L., Cao, J.J. and Du, C. (2019a), "A new experimental apparatus for sudden unloading of gas-bearing coal", B. Eng. Geol. Environ., 79, 857-868. https://doi.org/10.1007/s10064-019-01601-3.
  30. Wang, K. and Du, F. (2019), "Experimental investigation on mechanical behavior and permeability evolution in coal-rock combined body under unloading conditions", Arab. J. Geosci., 12(14), 1-15. https://doi.org/ 10.1007/s12517-019-4582-y.
  31. Wang, T., Wang, C. and Xue, F. (2021), "Acoustic emission characteristics and energy evolution of red sandstone samples under cyclic loading and unloading", Shock Vib. https://doi.org/10.1155/2021/8849137.
  32. Wu, M., Wang, J. and Russell, A. (2020), "DEM modelling of mini-triaxial test based on one-to-one mapping of sand particles", Geotechnique, 1-14. https://doi.org/ 10.1680/jgeot.19.P.212.
  33. Xie, J., Gao, M. and Zhang, R. (2020), "Gas flow characteristics of coal samples with different levels of fracture network complexity under triaxial loading and unloading conditions", J. Petrol. Sci. Eng., 195, 107606. https://doi.org/10.1016/j.petrol.2020.107606.
  34. Xu, J., Li, B. and Zhou, T. (2012), "Experimental study of deformation and seepage characteristics of coal under cyclic loading", Chin. J. Rock Mech. Eng., 33(2), 225-234. https://doi.org/10.13722/j.cnki.jrme.2014.s2.021.
  35. Zhang, B.J., Mei, C. and Huang, B. (2017), "Model tests on bearing capacity and accumulated settlement of a single pile in simulated soft rock under axial cyclic loading", Geomech. Eng., 12(14), 611-626. http://doi.org/10.12989/gae.2017.12.4.611.

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