Abstract
With the increase of mining depth in Chinese coal mines, the entry floor heave becomes one of the major engineering problems. This paper has studied the stress and displacement distribution around an entry in Buertai coal mine, China. The mechanism of floor heave is analyzed using the method of complex variable function. The influences of floor mechanical properties, longwall face advance, and mine water on the stability of the floor are then identified. The results show that (1) the floor moves towards the center under the concentration of the tangential stress, resulting in floor heave; (2) the floor stability is mainly influenced by the mechanical properties of the floor and the confining stress from the surrounding rock; and (3) the unnoticeable movement of the floor may be enlarged by the mining activity (face advance) and mine water. The proposed theoretical model is validated by the numerical modeling and the in situ. Good agreements are found between the theoretical analysis and the numerical modeling results and the in situ. It is thus believed that the complex variable function method can be used for analyzing the floor heave problem. Based on the mechanism of floor heave, we divide the control techniques into two categories: creation of a stress-relief entry and floor reinforcement. The techniques were practiced at two Chinese coal mines with good ground control effects.
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References
Chabaat M, Ayas H (2011) Complex variable Green's functions for crack-microcracks interactions. Key Eng Mater 465:123–128
Deng DM, Chen CD, Zheng YS, Peng X, Chen B, Peng YL., Zhou ML (2014) Nonparaxial propagation of complex variable function Cosh-Gaussian beams. Progress in Electromagnetics Research Symposium: 2517–2520
Jiang YD, Zhao YX, Liu WG, Li Q (2004) Research on floor heave of roadway in deep mining. Chin J Rock Mech Eng 23(14):2396–2401 (in Chinese)
Li C, Tie Y, Zheng YP (2010) Effects of opening hole geometric parameters on hole-edge stress field of plates according to a complex variable function model. Adv Mater Res 97-101:2614–2617
Li H, Li GL, Qiu DL (2011) Analysis of stress concentration for curvilinear holes by complex variable function method. Adv Mater Res 314-316:1052–1055
Li HM, Li HG, Song GJ, Wang KL (2016) Physical and mechanical properties of the coal-bearing strata rock in Shendong coal field. J China Coal Soc 41(11):2661–2671. https://doi.org/10.13225/j.cnki.Jccs.2016.1218
Li LC, Liu HH (2013) A numerical study of the mechanical response to excavation and ventilation around tunnels in clay rocks. Int J Rock Mech Min Sci 59:22–32
Lin P, Zhou YN, Liu HY, Wang C (2013) Reinforcement design and stability analysis for large-span tailrace bifurcated tunnels with irregular geometry. Tunn Undergr Space Technol 38(9):189–204
Lu AZ, Zeng XT, Xu Z (2016) Solution for a circular cavity in an elastic half plane under gravity and arbitrary lateral stress. Int J Rock Mech Min Sci 89:34–42
Lu AZ, Zhang LQ (2007) Complex function method for mechanical analysis of underground tunnel. Science Press, Beijing
Lu AZ, Zhang N, Zhang XL, Lu DH, Li WS (2015) Analytic method of stress analysis for an orthotropic rock mass with an arbitrary-shaped tunnel. International Journal of Geomechanics 15(4):04014068
Lu JK (1999) On a kind of biharmonic boundary value problems related to clamped elastic thin plates. Wuhan University Journal of Natural Science 4(3):251–255
Metlov KL (2010) Magnetization patterns in ferromagnetic nanoelements as functions of complex variable. Phys Rev Lett 105(10)
Qian HW (2015) Study on the deformation mechanism of water-rich coal roadway of Xiaojihan coal mine. Dissertation, China University of Mining and Technology
Shaposhnikova T (2012) Complex variables functions—inequality for entire functions involving their maximum modulus and maximum term. Atti della Accademia Nazionale dei Lincei, Classe di Scienze Fisiche, Matematiche e Naturali, Rendiconti Lincei Matematica e Applicazioni 23(3): 259–265
Sun J, Wang LG (2011) Numerical simulation of grooving method for floor heave control in soft rock roadway. Mining Science and Technology (China) 21:49–56
Sun XM, Chen F, He MC, Gong WL, Xu HC, Lu H (2017) Physical modeling of floor heave for the deep-buried roadway excavated in ten degree inclined strata using infrared thermal imaging technology. Tunn Undergr Space Technol 63:228–243
Tan Y, Guo WB (2016) Support theory and technology study for composite deformation of three-soft roadway under dynamic pressure. Coal Engineering 48(7):79–85. https://doi.org/10.11799/ce201607025
Xu Y, Chen J, Bai JB (2016) Control of floor heaves with steel pile in gob-side entry retaining. Int J Min Sci Technol 26:527–534
Zhao F, Yang SS, Li P, Li SF, Cui J (2015a) Study on control technology for floor heave in deep high-stress soft-rock roadway. Mining Safety and Environmental Protection 42(2):104–107
Zhao YM, Liu N, Zheng XQ, Zhang N (2015b) Mechanical model for controlling floor heave in deep roadways with U-shaped steel closed support. Int J Min Sci Technol 25(5):713–720
Acknowledgments
This research was supported by the National Basic Research Program (973 Program) (2013CB227903) and the National key R&D plan (2016YFC0801401). The authors are grateful to Professor Wang Jia-Chen in China University of Mining and Technology (Beijing), who guided the authors in the writing of this paper. In addition, the special thanks go to the editor as well as the reviewers of this paper, for their useful comments that improved the manuscript substantially.
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Yang, JH., Song, GF., Yang, Y. et al. Application of the complex variable function method in solving the floor heave problem of a coal mine entry. Arab J Geosci 11, 515 (2018). https://doi.org/10.1007/s12517-018-3875-x
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DOI: https://doi.org/10.1007/s12517-018-3875-x