Parameters of the Support Pressure near the Working, Mining a Coal Seam with Weak Rock Layers of its Roof and Soil


The problem of the stressed state of a carboniferous massif containing a coal seam worked out by a working belongs to the class of flat elastically plastic problems. To construct the stress field in the marginal extremely stressed zone of the seam, the Coulomb–Mohr criteria for the transition of the seam to the limiting state, as well as the methods of bulk medium mechanics developed by V.V. Sokolovsky, were used. If the rock layers of the soil and the roof of the coal seam are not strong enough, then the limiting state occurs first in it, and then at some distance from its edge and in the layers of rocks of the massif. It occurs when the reduced stress in the rock layers reaches the value of the reduced stress in the seam corresponding to the strength limit of the layers for uniaxial compression. After that, the seam and rock layers work together. Based on the constructed stress field of the seam, the problem of the stress state of the array is reduced to the problem of elasticity theory and solved by the method of boundary elements and successive approximations. According to the results of the computational experiment, the parameters of the reference pressure of the reservoir being worked out, depending on the width of the working, were obtained. Comparative estimates are given with similar parameters when mining a seam in the soil and roof of which there are strong layers of rocks.

1. Khristianovich S.A. About the crushing wave. Izvestiya AN SSSR. ONT = News of the USSR Academy of Sciences. DTS. 1953. № 12. pp. 1689–1699. (In. Russ.).
2. Khristianovich S.A. About the outburst wave. Izvestiya AN SSSR. ONT = News of the USSR Academy of Sciences. DTS. 1953. № 12. pp. 1679–1688. (In. Russ.).
3. Winton J.G. A review of energy associated with coal bursts. International Journal of Mining Science and Technology. 2018. Vol. 28. Iss. 5. pp. 755–761. DOI: 10.1016/j.ijmst.2018.08.004
4. Guo H., Yuan L. An integrated approach to study of strata behaviour and gas flow dynamics and its application. International Journal of Coal Science & Technology. 2015. №. 2. pp. 12–21.
5. Zhao B., Wen G., Sun H., Sun D., Yang H., Cao J., Dai L., Wang B. Similarity criteria and coal-like material in coal and gas outburst physical simulation. International Journal of Coal Science & Technology. 2018. Vol. 5. Iss. 2. pp. 167–178.
6. Cherdantsev N.V. A Certain Approach to Constructing the Solution to the Problem of Coal and Methane Outburst from a Marginal Seam Zone. Mechanics of Solids. 2022. Vol. 57. Iss. 8. pp. 2128–2150. DOI: 10.3103/S0025654422080301
7. Borisov A.A. Mechanics of rocks and massifs. Moscow: Nedra, 1980. 360 p. (In Russ.).
8. Bulychev N.S. Mechanics of the underground structures. Moscow: Nedra, 1994. 382 p. (In Russ.).
9. Fisenko G.L. Limit states of rocks around workings. Moscow: Nedra, 1976. 272 p. (In Russ.).
10. Cherdantsev N.V. Approach to Constructing a Hydraulic Fracture Trajectory in a Rock Mass Near a Mine Working. Mechanics of Solids. 2020. Vol. 55. Iss. 8. pp. 1372–1391. DOI: 10.3103/S0025654420080063
11. Cherdantsev N.V. Estimation of the Geomechanical State of the Marginal Zone of a Coal Seam Containing a Flimsy Layer. Mechanics of Solids. 2021. Vol. 56. Iss. 7. pp. 1307–1319.
12. Sokolovskiy V.V. Statics of granular medium. Moscow: Nauka, 1990. 272 p. (In Russ.).
13. Wei G. Study on the width of the non-elastic zone in inclined coal pillar for strip mining. International Journal of Rock Mechanics and Mining Sciences. 2014. Vol. 72. pp. 304–310. 
14. Galindo R.A., Serrano A., Olalla C. Ultimate bearing capacity of rock masses based on modified Mohr — Coulomb strength criterion. International Journal of Rock Mechanics and Mining Sciences. 2017. Vol. 93. pp. 215–225. DOI: DOI: 10.1016/j.ijrmms.2016.12.017
15. Lure A.I. Theory of elasticity. Moscow: Nauka, 1970. 940 p. (In Russ.).
16. Parton V.Z., Perlin P.I. The methods of elasticity mathematical theory. Moscow: Nauka, 1981. 688 p. (In Russ.). 
DOI: 10.24000/0409-2961-2023-12-14-20
Year: 2023
Issue num: December
Keywords : rock mass coal seam stress condition bearing pressure working soil and roof of the seam stress field theory of elasticity
  • Cherdantsev N.V.
    Dr. Sci. (Eng.), Chief Research Associate,, Federal Research Centre of Coal and Coal Chemistry of SO RAN, Kemerovo, Russian Federation
  • Cherdantsev S.V.
    Dr. Sci. (Eng.), Chief Research Associate, AO «NTs VostNII», Kemerovo, Russia