Vostoktsvetmet, Ust-Kamenogorsk, Kazakhstan:

A. A. Zhirnov, Chief Geotechnical Engineer
S. U. Abdrakhmanov, Head of Process and Investment Planning Department

Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia:

Yu. N. Shaposhnik, Leading Researcher, Professor, Doctor of Engineering Sciences
A. I. Konurin, Researcher, Candidate of Engineering Sciences, akonurin@yandex.ru

Measurements of natural stresses and jointing in rock mass at Orlov deposit under development by KAZ Minerals PLC are reported. Natural stresses were measured by the borehole slotter method. The absolute values of the resultant stresses are similar to the hydrostatic stress distribution. The jointing and faulting of rock mass is studied, three main sets of joints are identified, and their angles of incidence and dip are determined. The procedure of choosing designs of support for Orlov Mine is based on the Q-system by Barton. This approach allows assessing effects of such factors as strength and quality of rock mass, mining depth, cross section of roadways and stress state of surrounding rock mass, number and condition of joints, including their alteration. The implementation of the procedure based on the Q-system requires the lithological and geomechanical modeling of rock mass using refi ned physical parameters of ore and enclosing rocks. The technology of installation of reinforced ribs of sprayed shotcrete (RRS) by Norwegian method is described, and the mine support design is selected. It is shown that the reinforced ribs of shotcrete by the Q-system comply with the reinforcement in use in Kazakhstan mines (strips, mesh, braced-rib arch). The support system of reinforced arch of fiber-reinforced shotcrete in combination with rock bolts is calculated in ANSYS. The distribution of the principal stresses in the combination support elements and in adjacent rock mass is illustrated. The actual stresses in the fiber-reinforced shotcrete layer, as well as in mesh, or steel and cable bolts applied in rocks having Q-value 7–9 by Barton are not critical, and each type of the support systems preserves its load-bearing capacity. The developed algorithm and programming support for the automated selection of a support system, its design and the ground support standard enables elimination of miscalculations and allows acceleration of paperwork preparation.

1. Shkuratnik V. L., Nikolenko P. V. Methods of identification of deflected mode of rock massif. Moscow : Izdatelstvo MGGU, 2012. 111 p.
2. Zenko D. K., Uzbekova A. R. Main factors, having an influence on massif stability in RMR and Q. Gornyy informatsionno-analiticheskiy byulleten. 2004. No. 6. pp. 273–275.
3. Pantelidis L. Rock slope stability assessment through rock mass classification systems. International Journal of Rock Mechanics and Mining Sciences. 2009. Vol. 46, Iss. 2. pp. 315–325.
4. Jia M.-T., Wang L.-G. Evaluation of rockmass quality based on regionalization variable optimal estimation theory and RMR system in Jinchuan mine No. 3. Yantu Lixue. 2010. Vol. 31, No. 6. pp. 1907–1912.
5. Lowson A. R., Bieniawski Z. T. Critical assessment of RMR-based tunnel design practices: A practical engineer's approach. Rapid Excavation and Tunneling Conference : Proceedings. Englewood : Society for Mining, Metallurgy, and Exploration, 2013. pp. 180–198.
6. Aydan Ö., Ulusay R., Tokashiki N. A New Rock Mass Quality Rating System: Rock Mass Quality Rating (RMQR) and Its Application to the Estimation of Geomechanical Characteristics of Rock Masses. Rock Mechanics and Rock Engineering. 2014. Vol. 47, Iss. 4. pp. 1255–1276.
7. Aydan Ö., Ulusay R., Tokashiki N. Rock Mass Quality Rating (RMQR) System and Its Application to the Estimation of Geomechanical Characteristics of Rock Masses. Engineering Geology for Society and Territory : Proceedings of the XII IAEG Congress. Cham : Springer, 2015. Vol. 6. Applied Geology for Major Engineering Projects. pp. 769–772.
8. Santos V., da Silva A. P. F., Brito M. G. Prediction of RMR Ahead Excavation Front in D&B Tunnelling. Engineering Geology for Society and Territory : Proceedings of the XII IAEG Congress. Cham : Springer, 2015. Vol. 6. Applied Geology for Major Engineering Projects. pp. 415–419.
9. Barton N., Lien R., Lunde J. Engineering Classification of Rock Masses for the Design of Tunnel Support. Rock Mechanics and Rock Engineering. 1974. Vol. 6, Iss. 4. pp. 189–236.
10. Barton N. Some new Q-value correlations to assist in site characterisation and tunnel design. International Journal of Rock Mechanics and Mining Sciences. 2002. Vol. 39, Iss. 2. pp. 185–216.
11. Herbst M., Konietzky H. Numerical modelling of natural rock formations to estimate stability using the example of a sandstone massif in Saxony. Geomechanics and Tunneling. 2012. Vol. 5, No. 4. pp. 379–388.
12. Eremenko V. A., Rylnikova M. V., Esina E. N., Lushnikov V. N. Validation of estimation procedure for areas and values of stress concentration in mines. Gornyy informatsionno-analiticheskiy byulleten. 2014. No. 11. pp. 5–12.
13. Krupnik L., Shaposhnik Yu., Shaposhnik S. Ways of improvement of technology of anchor support at mining enterprises in Kazakhstan. Inzhenernaya zashchita. 2016. No. 1. pp. 54–59.
14. Eremenko V. A., Aybinder I. I., Patskevich P. G., Babkin E. A. Assessment of the state of rocks in underground mines at the Polar Division of Norilsk Nickel. Gornyy informatsionno-analiticheskiy byulleten. 2017. No. 1. pp. 5–17.
15. Krupnik L. A., Shaposhnik Yu. N., Shaposhnik S. N., Mametev Yu. I., Ibraev D. S. Experience of introduction of anchor support at underground mines in the Eastern Kazakhstan. Bezopasnost truda v promyshlennosti. 2015. No. 1. pp. 22–25.
16. Eremenko A. A., Fedorenko A. I., Kopytov A. I. Mining excavations and their support in the blasthazard areas of iron ore deposits. Novosibirsk : Nauka, 2008. 236 p.
17. Lushnikov V. N., Eremenko V. A., Sendi M. P., Bukher R. Underground excavation support in deformable and rockburst-hazardous rock mass conditions. Gornyi Zhurnal. 2014. No. 4. pp. 37– 44.
18. Rules of technical exploitation of mines, fields and pits, participating in mining of deposit of nonferrous, rare and precious metals. Moscow : Nedra, 1981. 109 p.