Author 1:
Name & Surname: Eremenko V. A.
Company: Institute for Comprehensive Exploitation of Mineral Resources—IPKON, RAS (Moscow, Russia)
Work Position: Principal Researcher
Scientific Degree: Doctor of Engineering Sciences
Contacts: eremenko@ngs.ru

Author 2:
Name & Surname: Louchnikov V. N.
Company: АМС Mining Consultants Pty Ltd. (Canada)
Work Position: Principal Mining Geotechnical Engineer

Author 3:
Name & Surname: Sandy M. P.
Company: АМС Mining Consultants Pty Ltd. (Australia)
Work Position: Director

Author 4:
Name & Surname: Shelukhin I. S.
Company: Nordgold (Moscow, Russia)
Work Position: Deputy Executive Director

The key problem of ground control in room-and-pillar mining in thin gently dipping veins is roof stability in the zone of stoping. Probability of roof collapse grows in permafrost formations with the temperature above 0.5 °С. In roofs of wide spans, ice has an adverse effect: tensile stresses develop in wider span roof and the resultant tensile cracks are gradually filled with ice. In course of time, accruing ice puts pressure on cracks, reduces roughness of their contact surfaces and thus weakens the roof rocks. Assessment of the extent of potential failure zone requires numerical analysis and 3D modeling based on reliable source data—values of natural stresses and physico-mechanical properties of rocks. Efficient method to evaluate roof collapse risk is to determine the roof rock collapsibility—the ratio of roof rock hardness to the undermining excavation size, that is expressed in terms of a hydraulic radius which is surface area/perimeter of excavation (plan view). For safe and efficient mining at Irokinda deposit, it is required to implement regular monitoring of stresses and strains in rocks, with accounting for the research findings and developed recommendations. The work is accomplished in the framework of the Fundamental Research Program “Theoretical Advance in the Area of Hard Mineral Mining in Conformity with the State-of-the Art and Prospective Change of the Mineral and Raw Materials Base of Russia” (IV.8.3).

The authors appreciate participation of I. N. Semenov, Manager for Underground Mining, Nordgold, in this research work.

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