Detection of high seismic activity zones in mine field during stoping at the Taimyrsky Mine

Deep-level mining in the Arctic zone of the Norilsk industrial region conditions intensified research on prediction and prevention of geodynamic events which cause extensive material damage to plants and facilities in the influence zone of mining operations. Investigative detection and distribution of seismic activity zones was carried out during stoping at the Taimyrsky Mine using the microseismic method and system Relos-R/SH-64-N. Positions and shapes of seismic zones were determined in neighborhood of extraction panels at the depths from 400 to 1700 m. The patterns of the number and energy of seismic events over the period of 2023–2024 were compared. The seismic activity in 2023 grew in terms of the total energy by 80 % and in terms of the number of events by 37 %. All in all, 10713 seismic events were recorded with the total energy of 3.7∙106 J, including 38 events with the energy above 4500 J. During the year, 37 panels were subjected to extraction, and seismic zones of various shape from 300 to 3400 m² in size appeared. It is found that mining sequence in extraction panels influences initiation of seismic events at different depths. The geomechanical assessment of rock mass was carried out using the seismic activity index Кs which was 0.03–0.13 in the most seismically active extraction panels 8–10 and 25. The zonal distribution was found for large seismic events with the energy higher than 4500 J in the roof and floor of enclosing rock mass, and in the ore body ahead of stoping. The results agree with the monitoring parameter F which reaches the maximum values F = 348–450 in panels 12, 13 and 9, 12, respectively. Using the experimental research data, the sources of seismic events are located in the roof and floor of enclosing rock mass, and in the ore body, and this allows analyzing and, if necessary, optimizing the mining sequence in extraction panels to promote geodynamic safety of mining operations.