DBPapers
DOI: 10.5593/SGEM2015/B13/S5.132

STRESSED ROCK MASS IN NEAR-WALL OPEN-PIT’S ZONE: MICROSEISMIC MONITORING RESULTS

A. Kozyrev, M. Kagan, D. Chernobrov
Friday 7 August 2015 by Libadmin2015

References: 15th International Multidisciplinary Scientific GeoConference SGEM 2015, www.sgem.org, SGEM2015 Conference Proceedings, ISBN 978-619-7105-33-9 / ISSN 1314-2704, June 18-24, 2015, Book1 Vol. 3, 1019-1026 pp

ABSTRACT
Microseismic monitoring data analysis and interpretation allow assessing impact of intensive mining operations on macroscopic stability of the wall’s rocks, identifying seismic active geological structures and assessing walls’ deformation related to seismic events.
The study used the data obtained with a microseismic monitoring system applied in the Zhelezny mine, “Kovdorsky GOK” JSC, Murmansk region, Russia. Seismic information was treated with computer technologies, including software for treating and editing seismograms. Cluster analysis statistic methods were used to define seismic active zones. The method of modeling seismic focal mechanisms was applied.
As a result of studies, there were defined correlation dependencies which connect dynamics of microseismic activity in the near-wall rock mass and deformation processes development. Seismic active areas were revealed during the studies such as under the open-pit bottom, in the vicinity of south-eastern wall and in the geological faults zone. Modeling of seismic focal mechanisms have revealed action of shearing stresses oriented parallel to the pit wall and tensile stresses acting normal to the pit wall. Destructions inside of the rock mass as a result of these stresses occur, in general, in the form of ruptures oriented to the dip.
The information given is of interest for the specialists dealing with geophysical control for geological media state under mad-made impacts and geomechanics of open and underground mining operations.

Keywords: seismicity, open-pit, monitoring, stresses, deformations