Nosov Magnitogorsk State Technical University, Magnitogorsk, Russia:

S. E. Gavrishev, Director of the Institute of Mining and Transport, Professor, Doctor of Engineering Sciences
I. A. Pytalev, Professor, Candidate of Engineering Sciences, pytalev_ivan@mail.ru

Institute of Mining, Ural Branch, Russian Academy of Sciences, Yekaterinburg, Russia:

O. V. Zoteev, Chief Researcher, Professor, Doctor of Engineering Sciences

South Ural State University, Chelyabinsk, Russia:

T. S. Kravchuk, Associated Professor, Candidate of Engineering Sciences

The article offers the estimation procedure for slope stability in a mined-out open pit in the period of its natural flooding at closure. The change in the slope stability factor in the open pit is analyzed in the current condition of mining, in the pit flooded by 0.3–0.5 of its depth, and in the pit filled with thickened tailings. With regard to dynamics of strength reduction in the pitwall rock mass as a result of natural flooding of the pit, the slope stability control by loading the pitwall by the current thickened tailings is discussed. The proposed approach is tested in the Aleksandrinsky mine. Efficiency of thickened tailings in recovery of long-term stability factor of the pitwalls during reclamation is proved. The maximum ranges of potential deformation propagation are delineated, and it is found that external dumps exert zero influence on total stability of the undermined southern pitwall. The dumps placed on the southern pitwall are located beyond the zone of active pressure of the pitwall slope, exert no influence on the total stability of the southern pitwall and will preserve their external boundary during and after the open pit mine closure. The slope stability control in open pits using thickened tailings allows undertaking reclamation of mining-disturbed lands with all industrial and ecological safety requirements fulfilled.

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