Institute of Coal, Federal Research Center for Coal and Coal Chemistry, Siberian Branch, Russian Academy of Sciences, Kemerovo, Russia:

E. N. Kozyreva, Head of Laboratory, Candidate of Engineering Sciences
M. V. Shinkevich, Senior Researcher, Candidate of Engineering Sciences, max-valerich@rambler.ru

Ground control is connected with monitoring of deformations of enclosing rock mass in the course of mining for ensuring stability of underground openings. One of the negative consequences of redistribution of rock pressure in an extraction panel during mining operations is swelling of floor rocks. The present article considers mining conditions of coal seams using the features of formation and development of nonlinear structurization of rock mass during longwall advance, earlier revealed at the Institute of Coal. The calculation basis is the developed parametrical model of geomechanical processes in rock mass during mining using the longwall top coal caving method. The rock mass is considered at the first approximation as a uniform isotropic medium without regard to mechanical properties of rocks. The model rock mass is presented as a set of manmade geomechanical layers. Their formation begins from a coal seam being mined and develops with the longwall advance with regard to elastic energy of rock mass. In the manmade change of external conditions, the rock mass rebates its energy potential via arching and movement. The bodies of “arches of movement” tend to paraboloids in shape. Formation of such shapes corresponds to the concept of minimum energy spend for the creation of a new surface under uniaxial unloading. The height of the arches-paraboloids is equal to the thickness of geomechanical layers at different scales of the structural hierarchy of rock mass. The horizontal dimension of the archesparaboloids is divisible by a longwall length. It is possible to detect sites of increased rock pressure applied to the boundaries and roof support of underground openings by means of geometrical overlapping of circles having diameters equal to the basal parts of displacement arches with load-bearing edges. Integration of the displacement arches of the adjacent extraction panels leads to connection of their mined-out areas and to gas cross-flow between them. The cardinally new approach to understanding geomechanical processes in rock mass can allow predicting adverse phenomena of rock pressure and the increased methane emission during high-rate longwalling.

1. Jinglin Wen, Husheng Li, Fuxing Jiang, Zhengxing Yu, Haitao Ma et al. Rock burst risk evaluation based on equivalent surrounding rock strength. International Journal of Mining Science and Technology. 2019. Vol. 29, Iss. 4. pp. 571–576.
2. Weizhang Liang, Guoyan Zhao, Xi Wang, Jie Zhao, Chunde Ma. Assessing the rockburst risk for deep shafts via distance-based multi-criteria decision making approaches with hesitant fuzzy information. Engineering Geology. 2019. Vol. 260. 105211. DOI: 10.1016/j.enggeo.2019.105211
3. Simser B. P. Rockburst management in Canadian hard rock mines. Journal of Rock Mechanics and Geotechnical Engineering. 2019. Vol. 11, Iss. 5. pp. 1036–1043.
4. Chambers D. J. A., Boltz M. S., Richardson J. R., Finley S. A. Application of subspace detection on a surface seismic network monitoring a deep silver mine. Deep Mining 2017: Eighth International Conference on Deep and High Stress Mining. Perth : Australian Centre for Geomechanics, 2017. pp. 141–154.
5. Hellan K. Introduction to Fracture Mechanics. New York : McGraw Hill , 1985. 30 2 p.
6. Drzewiecki J. Neue Verfahren zur Bekämpfung der Gebirgsschlaggefahr. Glückauf. 2002. No. 2(3). pp. 18–21.
7. Jacobi O. Praxis der Gebirgsbeherrschung. 2, neu bearbeitete und mit neuen Ergebnissen erweiterte Auflage. Essen : Verlag Glückauf GmbH, 1981.
8. Artemev V. B., Korshunov G. I., Loginov A. K., Shik V. M. Dynamic phenomena of rock pressure. Saint-Petersburg : Nauka, 2009. 347 p.
9. Hui Zhou, Haitao Liu, Dawei Hu, Fan Zhang, Fanjie Yang et al. Estimation of the effective thermal properties of cracked rocks. European Journal of Environmental and Civil Engineering. 2016. Vol. 20, No. 8. pp. 954–970.
10. Xu J. L., Ni J. M., Xuan D. Y., Wang X. Z. Coal mining technology without village relocation by isolated grout injection into overburden. Coal Science and Technology. 2015. Vol. 43(12). pp. 8–11.
11. Lei Nie, Hongfei Wang, Yan Xu, Zechuang Li. A new prediction model for mine subsidence deformation: the arc tangent function model. Natural Hazards. 2015. Vol. 75, Iss. 3. pp. 2185–2198.
12. Dayang Xuan, Binglong Wang, Jialin Xu. A shared borehole approach for coal-bed methane drainage and ground stabiliz ation with grouting. International Journal of Rock Mechanics and Mining Sciences. 2016. Vol. 86. pp. 235–244.
13. Antipov I. V., Stadnyuk E. D., Kozyr S. V. Interconnection of technological operations in longwall with geomechanical processes in rock mass. UkrNIMI’s Transactions. Donetsk : UkrNIMI NAN Ukrainy, 2015. No. 15. pp. 9–20.
14. Lobkov N. I., Kosyr S. V., Krizhanovskaya L. N., Arutyunyan R. M. Arutyunyan R. M. Mechanism of rock layer movement over the waste area. UkrNIMI’s Transactions. Donetsk : UkrNIMI NAN Ukrainy, 2015. No. 15. pp. 21–30.

15. Litvinskiy G. G. Stress-strain state of rock mass around a longwall. Transactions of the Donetsk State Technical University. Alchevsk, 2016. No. 3(46). pp. 16–24.
16. Kotyashev A. A., Shemenev V. G. Testing hard rock fracture technology using decoupled charges. Gornyi zhurnal Kazakhstana. 2015. No. 7. pp. 30–34.
17. Kasyanenko A. L. A new method to ensure stability of floor rocks in extraction panels. Rock Pressure : Collected Works. Donetsk, 2016. No. 2(29). pp. 17–27.
18. Cherdantsev N. V., Shadrin A. V. A fluid pressure-loaded single crack located in a rock massif propagation trajectory calculation. Vestnik Nauchnogo tsentra po bezopasnosti rabot v ugolnoy promyshlennosti. 2017. No. 4. pp. 18–26.
19. Shadrin A. V., Klishin V. I. The improvement of automated dynamic phenomena forecast methods during roof weakening and preventive hydrotreating. Vestnik Nauchnogo tsentra VostNII po promyshlennoy i ekologicheskoy bezopasnosti. 2017. No. 3. pp. 31–35.
20. Taylakov O. V., Utkaev E. A., Smyslov A. I., Kormin A. N. Physical modelling of coal seams filtration properties fluctuation. Vestnik Kuzbasskogo gosudarstvennogo tekhnicheskogo universiteta. 2014. No. 6(106). pp. 13–16.
21. Kozyreva E. N., Shinkevich M. V. Peculiar features of gas-geomechanikal processes at a mine coal extraction section. Vestnik Nauchnogo tsentra po bezopasnosti rabot v ugolnoy promyshlennosti. 2010. No. 2. pp. 28–35.
22. Polevshchikov G. Ya., Kozyreva E. N., Shinkevich M. V., Leontyeva E. V. Induced structuring of rock mass under coal mining. Gornyi Zhurnal. 2017. No. 4. pp. 19–23. DOI: 10.17580/gzh.2017.04.03
23. Available at: https://docs.cntd.ru/document/573264171 (accessed: 15.06.2021).