Kamp, C, Conley, A, Collins, DS, Preiksaitis, M, Butler, T & Shumila, V 2022, 'Use of seismic tomography to aid rock mechanics interpretation at New Afton B3 block cave mine', in Y Potvin (ed.), Caving 2022: Fifth International Conference on Block and Sublevel Caving
, Australian Centre for Geomechanics, Perth, pp. 461-472, https://doi.org/10.36487/ACG_repo/2205_31
New Gold’s New Afton gold-copper mine is successfully mining different regions of the orebody using block caving. The present block cave at the mine, B3, successfully initiated steady state caving below the completed Lift 1 Block Cave in January 2022 with 8.8 MT (probable tonnes). Instrumentation monitoring methods in B3 include seismic event location, optical and metallic time-domain reflectometer (TDR), Elexon Geo4Sight and Elexon Beacons, and are being used to interpolate the 3D shape of the cave profile. For the first time at this mine, seismic tomography is being used to help interpret the stress and damage state of the rock mass around the cave.
This paper presents results from the seismic tomography and the interpretation of the high and low stress regions. Regions of rock mass destressing are determined in seismically active areas as well as aseismic zones. Tomographic velocity differences show that stress migration is occurring within certain regions of the abutments and above as the block cave growth progresses. The seismic tomography interpretation, accompanied by geological information and other geotechnical instrumentation, is helping to improve the safety and productivity of this mining operation.
Keywords: seismicity, tomography, caving, stress, instrumentation, safety
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