Siberian State Industrial University, Novokuznetsk, Russia:

Yu. M. Govorukhin, Associate Professor, Candidate of Engineering Sciences, govorukhin_ym@mail.ru
S. V. Rib, Senior Lecturer
A. M. Nikitina, Associate Professor, Candidate of Engineering Sciences
V. N. Fryanov, Head of Chair, Professor, Doctor of Engineering Sciences

The modeling results are presented for the process of rock mass movement during fully mechanized longwall mining. It is found that deformations in the zone of rock movement alter gas permeability of coal, which results in formation of gas holders. Numerical modeling of geomechanical processes finds parameters of rock falls and methane-and-air flow in mined-out areas. The applied authoring bundled software Geomechanics (Geotechnology Chair, Siberian State Industrial University) makes use of the finite element method. Modeling is implemented for a mine area in the Baidai economic–geological region in Kuzbass. The scope of modeling embraces assessment of rock mass behavior in the principal profile of movement zone along trajectory of the fully-mechanized longwall. The studies determine caving steps in each layer/sublayer in the roof, which form a caving zone. It is found that fall of roof rocks in the preset conditions of the extraction site occurs in the mode of arching as the roof slab falls not to the full thickness but fails in the form gradual spalling. This approach allows predicting primary and subsequent steps of roof caving during face advance, as well as the height of the caving zone, loosening and compaction of rocks. These parameters are required for the aerodynamic resistance design in mined-out areas and for the gas-dynamic modeling of gas holder formation.

1. Shuvalov Yu. V., Korshunov G. I., Montikov A. V., Istomin R. S., Sufiyarov A. M.,Yutyaev E. P. Gas dynamics and geomechanics of coal massive at high speed of facing. GIAB. 2011. No. 6. pp. 80–88.
2. Remezov A. V., Klimov V. V., Zharov A. I., Kostinets I. K., Kochkin R. O. Modern perspectives on existing protection technologies of mine workings contouring extraction pillar. Vestnik Kuzbasskogo gosudarstvennogo tekhnicheskogo universiteta. 2015. No. 2. pp. 65–72.
3. Stadnyuk E. D. Mine instrumental observations of surrounding rock convergence inactive breakage faces. Izvestiya Tulskogo gosudarstvennogo universiteta. Nauki o Zemle. 2013. No. 3. pp. 126–135.
4. Mustafin M. G. Effect of longwall face advance on failure dynamics in coal roof rocks. GIAB. 2008. No. 1. pp. 17–22.
5. Pavlova L. D., Fryanov V. N. The influence of the geomechanical processes on the parameters of gas header in the area of earth movement during mining series of coal strata. GIAB. 2011. No. 8. pp. 70–78.
6. Galvin J. M. Ground Engineering: Principles and Practices for Underground Coal Mining. Cham : Springer International Publishing, 2016. 693 p.
7. Esterhuizen G., Karacan C. A methodology for determining gob permeability distribution and its application to reservoir modeling of coal mine longwalls. The Power of Mining: Energy’s Influence : SME Annual Meeting 2007 and CMA 109th National Western Conference. Denver, 2007. pp. 477–482.
8. Whittles D. N., Lowndes I. S., Kingman S. W., Yates C., Jobling S. Influence of geotechnical factors on gas flow experienced in a UK longwall coal mine panel. International Journal of Rock Mechanics and Mining Sciences. 2006. Vol. 43, Iss. 3. pp. 369–387.
9. Xia-Ting Feng. Rock Mechanics and Engineering. Leiden : CRC Press/Balkema, 2017. Vol. 5: Surface and Underground Projects. 760 p.
10. Vakili A., Albrecht J., Gibson W. Mine-Scale Numerical Modelling of Longwall Operations. Proceedings of the 2010 Coal Operators’ Conference. Wollongong, 2010. pp. 115–124.
11. 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. Vol. 2, Iss. 1. pp. 12–21.
12. Gharehdash S., Barzegar M. Numerical Models Currently Being Developed for Use in Mining Industry. Mine Planning and Equipment Selection : Proceedings of the 22^nd MPES Conference. Cham : Springer International Publishing, 2014. pp. 481–490.
13. Domrachev A. N., Govorukhin Yu. M., Krivolapov V. G., Lipatin V. I., Paleev D. Yu. Methodology for the selection and justification of a mine stopping reinforcement. Miner’s week – 2015 : Reports of the XXIII International Scientific Symposium. Moscow : Izdatelstvo NITU «MISiS», 2015. pp. 141–150.
14. Domrachev A. N., Rib S. V. Synthesis of 2D and 3D models to predict nonuniform pillar stabilty in coal mines. Modeling and High Information Technologies in Technology, Society and Economy : Proceedings of IV All-Russian Scientific and Practical Conference with International Participation. Novokuznetsk, 2016. pp. 211–215.
15. Rib S. V., Frianov V. N. Develop a set of problem-oriented programs for the numerical modeling of the stress-strain state of heterogeneous coal pillars. GIAB. 2015. No. 3. pp. 367–371.
16. Govorukhin Yu. M. Input data procedure for modeling processes in mined-out area. High Technologies of Mining and Usage of Mineral Resources : Collection of scientific articles. Novokuznetsk, 2016. pp. 112–115.
17. Rib S. V., Basov V. V. Methods of initial data preparing for two-dimensional problems solution in numerical modeling of inhomogeneous coal pillars. Vestnik Sibirskogo gosudarstvennogo industrialnogo universiteta. 2014. No. 4. pp. 11–14.
18. Borisov A. A. Mechanics of rocks and rock masses. Moscow : Nedra, 1980. 360 p