Polar Division, Norilsk Nickel Mining and Metallurgical Company (Talnakh, Russia)

Anokhin A. G., Director, Geodynamic Safety Center, Candidate of Engineering Sciences, Phone: +7(3919) 45-21-57
Semen’ko K. A., Chief Engineer, Mining and Geology Department
Darbinyan T. P., Chief Engineer, Oktyabrsky Mine

National Mineral Resources University (University of Mines) (Saint-Petersburg, Russia)
Tsirel’ S. V., Chief Researcher, Doctor of Engineering Sciences

VNIMI Inter-Industry Scientific Center (Saint-Petersburg, Russia)
Mulev S. N., Head of Laboratory

The research work was executed, interalios, by L. V. Kakoshina, Chief of Department of the Geodynamic Safety Center (GSC); E. V. Rodionova, Assistant Chief of Department, GSC; O. V. Sitnikova, Principal Engineer of Department, GSC; M. V. Tereshenko, Category 2 Engineer of Department, GSC.

Amount of seismic events, their total energy, slope of frequency curve and a generalizing factor F are the characteristics of a seismic process in a mine. Yet it is not only the numerical characteristic but also the process developing conditions that are required for estimation of seismic hazard. According to the long-term observations, the above listed parameters of seismic activity in a rock mass, at the same mining-and-geological characteristics, are utmost affected by damage state of the rock mass, including its altered condition during and after mining—displacement, backfilling, blasting and destress hole drilling. The article presents the procedure of accounting for the mentioned factors in plotting the rockburst-hazardous zones based on seismic data. The essence of the procedure is division of spatial and time changes in the values of F into the normal rock mass response to various disturbing effects (damage) and abnormal subsidiary alteration characterizing geodynamic hazard development in the rock mass. The result of the division is the space- and time-graded critical levels of seismic activity. The differentiated parameters should be carefully introduced so that not to consider a hazardous seismic activation the normal rock mass response to mining operations and not to overestimate seismic activity beyond the mining area limits. This prudence is attained within the suggested formulas owing to introduction of narrow constraints for reduction factors and step-up ratios of critical values, weighting of contribution of each factor in the change of the critical value of F using three-layer architecture neuron network based on the factual data on seismic activity in mines of the Polar Division of the Norilsk Nickel Mining and Metallurgical Company, and averaging of the reduction factors and step-up ratios of the critical value of F in the final formula. Later on, while the methodology and the related procedures are elaborated, these constraints can be relaxed.