Institute of Mining, Soligorsk, Belarus:

B. I. Petrovsky, Chief Researcher, Doctor of Engineering Sciences, sigd@list.ru
V. A. Misnikov, Leading Researcher, Candidate of Engineering Sciences

Institute of Mining, Soligorsk, Belarus¹ ; Belarusian National Technical University, Minsk, Belarus²:

K. A. Erokhin^1,2, Researcher, Post-Graduate Student

Belarusian National Technical University, Minsk, Belarus²; 3Belaruskali, Soligorsk, Belarus¹:

A. B. Petrovsky^2,1, Deputy Chief Mining Engineer

Extraction of the remaining reserves at the Starobinsk potassium salt deposit is associated with degradation of geological conditions as the content of clay beds in roof rocks increases with depth. The article presents the underground test data on the most promising techniques of roof support in development entries in deep-level unstable rocks in the Starobinsk potassium salt deposit. In an operating mine, various combinations of different support types and ground control approaches were tested, namely, compensation voids (slotting, racking) and long roof bolting. It is found that the maximum efficiency of development heading support is achieved with the combination of destressing headings and compensation slots. These flow charts are applicable to a depth of 860–900 m at the clay bed content of 35%. At the depths greater than 900 m and at the clay bed content higher than 35%, each underground excavation should have a specific support type. In extremely complex conditions at any depth and at the clay bed content from 35 to 60% in the roof, the support design for long underground openings with a span to 3.8 m, without slots in the sidewalls can involve roof scaling up to the roof arch (pressure arch) and installation of special-shape and expansion-type yielding support in sidewalls.

1. Konstantinova S. A., Aptukov V. N. Some problems of deformation and failure of salt rocks. Novosibirsk : Nauka, 2013. 191 p.
2. Тarakanov V. A., Golovaty I. I., Polyakov A. L., Misnikov V. A., Karaban D. T. Roadways supporting while developing the Starobin deposit at big depths. Gornyi Zhurnal. 2010. No. 8. pp. 36–38.

3. Patiyuk S. I., Petrovsky Yu. B., Prushak V. Ya. Support of deep-level permanent and development excavations at the Starobin deposit. Gornyi Zhurnal. 2018. No. 8. pp. 70–75. DOI: 10.17580/gzh.2018.08.10
4. Prushak V. Ya. Forecast of mine workings stability during preparation by deep mining of the second potash seam’s reserves at the Starobin deposit. Annual of the University of mining and geology st. Ivan Rilski. 2012. Vol. 55. Part II. Mining and Mineral Processing. pp. 51–56.
5. Polyakov A. L., Misnikov V. A., Lutovich E. A., Erokhin K. A. Maintaining of Starobin potash deposit workings using special types of the support. Part 1. Requirements for maintaining of the workings using increased bearing capacity anchors. Gornaya mekhanika i mashinostroenie. 2017. No. 3. pp. 37–45.
6. Coleman T. J., Neely D. D. Developments in stiff ground support in deep potash operations at the Vanscoy Mine. Ground Support 2019: Proceedings of the Ninth International Symposium on Ground Support in Mining and Underground Construction. Sudbury, 2019. pp. 519–532.
7. Charlie C. Li. Principles of rockbolting design. Journal of Rock Mechanics and Geotechnical Engineering. 2017. Vol. 9, No. 3. pp. 396–414.
8. Funk C., Appleyard J., Braun J., Derkach J. How Geoscientists are Making Potash Mines Safer. Canadian Journal of Exploration Geophysics. 2017. Vol. 42, No. 4. pp. 15–17.
9. Sergeev S., Zinchenko A., Yurchenko G. In-situ estimation of stress-strain behavior of reinforcedconcrete landing support. Geomechanics and Geodynamics of Rock Masses : Proceedings of the 2018 European Rock Mechanics Symposium. London : Taylor & Francis Group, 2018. Vol. 2. pp. 1311–1315.
10. Eremenko V. A., Neguritsa D. L. Efficient and active monitoring of stresses and strains in rock masses. Eurasian Mining. 2016. No. 1. pp. 21–24. DOI: 10.17580/em.2016.01.02
11. Galchenko Yu. P., Eremenko V. A., Myaskov A. V., Kosyreva M. A. Solution of geoecological problems in underground mining of deep iron ore deposits. Eurasian Mining. 2018. No. 1. pp. 35–40. DOI: 10.17580/em.2018.01.08
12. Grechishkin P. V., Razumov E. A., Zayatdinov D. F., Chugaynov S. S. Modern technologies of rock bolting and cable bolting: perspectives on implementation for different mining methods and mine conditions. GIAB. 2016. No. 10. pp. 182–200.