National University of Science and Technology–MISIS, Moscow, Russia¹ ; Don State Technical University, Rostov-on-Don, Russia²:

Pleshko M. S.^1,2, Professor, Doctor of Engineering Sciences, mixail-stepan@mail.ru

National University of Science and Technology–MISIS, Moscow, Russia:
Pankratenko A. N., Head of Department, Professor, Doctor of Engineering Sciences

Platov South-Russian State Polytechnic University (NPI), Novocherkassk, Russia:
Nasonov A. A., Associate Professor, Candidate of Engineering Sciences

Management Company ELSI LLC, Yakutia, Russia:
Isaev A. S., Chief Executive Officer, Candidate of Engineering Sciences

Currently Skalisty Mine in the Norilsk Region of Russia is finishing construction of two vertical shafts 2050 m deep in very difficult geological and climatic conditions. This study uses the geotechnical monitoring data on one shaft and the stage-wise numerical modeling results to reveal mechanisms of stresses in the shaft lining and to assess efficiency of technologies and designs in use. It was found that high stress relaxation took place in the region around the shaft before installation of permanent support. The measured normal and shear stresses in shotcrete lining exceeded the calculated values, and the asymmetry of the stresses was observed in the cross-section of the shaft. Regarding the permanent support, the measured maximal compressive stresses were lower than the calculation. The analysis confirms the ultra deep shaft stability. The assumed designs and technologies for the ultra deep shaft construction are optimal.

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