Norilsk Nickel’s Polar Division, Norilsk, Russia:

V. P. Marysyuk, Chief Geotechnologist – Director of Center for Geodynamic Safety, Candidate of Engineering Sciences, marysyukvp@nornik.ru
S. Yu. Shilenko, Deputy Director of Mining Practice Department

Gipronikel Institute, Saint-Petersburg, Russia:

A. V. Trofimov, Head of Center for Physical and Mechanical Research, Candidate of Engineering Sciences

Norilsk Geologiya, Norilsk, Russia:

S. V. Kuzmin, Leading Geomechanic, Candidate of Engineering Sciences

During operation of long main ore chutes at great depths, in heavily fractured rocks with poor physical and mechanical properties, the sidewalls gradually disintegrate and the ore chutes expand. The resultant void adversely affects stability of permanent underground excavations nearby. Disintegration of sidewalls worsens performance of ore chutes and increases technological hazards. Such situations can reduce mining safety and economic efficiency. The cause of the sidewall disintegration in ore chutes is the multi-factor synergetic impact exerted by geological conditions, stress–strain behavior of rock mass, operating mode, size and shape of an ore chute, grain size composition of ore, ore flow hanging ability and its recoverability methods, as well as design of the sidewall support. The problem of destruction in ore chutes subjected to highly intensive operation exists worldwide, especially in deep mines, which explains the comprehensive studies in this field, based on the empirical approaches as a rule. In the meanwhile, irrespective of the stability prediction or estimation method applied, the decision-making on the construction sites for such critical mine objects as main ore chutes should be based on the integrated geotechnical research of rock mass, which can reduce potential risk of uncontrolled processes. This study estimated alternative locations of a new ore chute using an integrated approach, including physical and mechanical properties of enclosing rock mass, based on tests of cores from geotechnical holes drilled on the would-be ore chute construction site, and concurrent geotechnical description of the core, which allowed stability analysis using the rock mass rating systems.
The authors appreciate participation of A. E. Rumyantsev, T. K. Burdukov, A. V. Fedoseev, K. E. Breus and A. P. Kirkin in this study.

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