Kamp, C 2022, 'Management of production drift convergence and redevelopment', in Y Potvin (ed.), Caving 2022: Fifth International Conference on Block and Sublevel Caving
, Australian Centre for Geomechanics, Perth, pp. 831-848, https://doi.org/10.36487/ACG_repo/2205_57
New Afton Mine is a block caving operation, located approximately 10 kilometres outside of Kamloops and 350 kilometres northeast of Vancouver in British Columbia. The New Afton orebody has a unique combination of geometric and geotechnical conditions, including a long and narrow footprint which is highly faulted and hence comprises large areas of poor ground, all of which is subject to a relatively high major horizontal principal stress. The initial deformations (convergence) experienced on the production level (extraction level) of the Lift 1 West Cave proved relatively manageable; however, as mining moved eastward towards the Lift 1 East Cave, which comprised significantly poorer rock mass quality, deformation rates increased causing substantial damage and subsequent repair of the footprint.
Block caving in a poor rock mass subject to high cave induced stress changes typically experience large plastic deformations which manifest as drive convergence and in some cases complete drive closure. Such conditions require comprehensive extraction drive and drawpoint redevelopment (rehabilitation), which consequently increases operating costs and constraints production. A conceptual model of convergence and comprehensive ground control rehabilitation strategy for existing drawpoints and extraction drives has been implemented at the New Afton Mine with the aim of managing rock mass damage and maintaining drawpoint integrity until mining is exhausted. A review of ground support and rehabilitation methods along with the conceptual convergence model are discussed. An example case of a drawpoint and associated extraction drive area that was successfully recovered following high convergence is presented.
Keywords: convergence, ground support, rehabilitation, caving
Beck 2017, New Afton Internal Document, New Afton Mine, Kamloops.
Bieniawski, ZT 1989, Engineering Rock Mass Classifications, John Wiley & Sons, New York, pp. 251.
Brenchley, P, Snyman, LA, Samosir, J & Coxon, B 2013, ‘Redevelopment support at Northparkes Mines’, in Y Potvin & B Brady (eds), Ground Support 2013: Proceedings of the Seventh International Symposium on Ground Support in Mining and Underground Construction, Australian Centre for Geomechanics, Perth, pp. 451–460,
Evans P, 2021, ‘Improving convergence monitoring using lidar data at Rio Tinto’s Argyle diamond mine’, Emesent and Minelidar White Paper, viewed April 15 2022,
Febrian, I, Yudanto, W, Rubio, E 2004, ‘Application of convergence monitoring to manage induced stress by mining activities at PT Freeport Indonesia Deep Ore Zone Mine’, MassMin 2004, Instituto de Ingenieros de Chile, Santiago, pp. 269–272.
Firmanulhaq, SA, Kamarea, J, Hasan, R, Putra, F & Salim, F 2017, ‘Lessons learnt from egress drift excavation through a minor pillar in an extraction level, Deep Ore Zone mine, Freeport Indonesia, Papua’, in M Hudyma & Y Potvin (eds), UMT 2017: Proceedings of the First International Conference on Underground Mining Technology, Australian Centre for Geomechanics, Perth, pp. 645–654,
Ginting, AS, Alpeki, H 2018, ‘Ground deformation monitoring by convergence measurement and damaged area mapping in Deep Ore Zone (DOZ) Mine at Pt. Freeport Indonesia’, Prosiding XXVII Dan Kongres X Perhapi (Proceedings of the XXVII and X Perhapi Congress).
Haveman, BR, Hemstad, EA, Shaffer, AL, Gilbride, LJ & Kamp, CL 2021, Horizontal Principal Stress Measurement & Determination of Stress Gradient at the New Afton Mine, Kamloops, British Columbia, presented at the Grand Junction Geological Society.
Millán, J & Quezada, O 2012, ‘Evolution of damage in galleries by opening of the structural array, Esmeralda Mine, El Teniente Deposit: case study’, MassMin 2012: Proceedings of the 6th International Conference & Exhibition on Mass Mining, Canadian Institute of Mining, Metallurgy and Petroleum, Sudbury.
Moss, A, Kaiser, PK 2022, ‘An operational approach to ground control in deep mines’, Journal of Rock Mechanics and Geotechnical Engineering, vol. 14, issue 1, pp. 67–81.
Pardo, C, Beck, D, Villaescusa, E & Brzovic, A, 2012, ‘Back analysis of intensive rock mass damage at the El Teniente mine’, Proceedings of the 2012 Australian Mining Technology Conference.
Sahupala, HA & Srikant, A 2007a, ‘Assessment of pillar damage at the extraction level in the Deep Ore Zone (DOZ) mine, PT Freeport Indonesia’, First International Symposium on Block and Sub-Level Caving, The Southern African Institute of Mining and Metallurgy, Johannesburg.
Sahupala, HA & Srikant, A 2007b, ‘Geotechnical inputs for cave management in the DOZ block cave’, Proceedings of the 1st Canada - U.S. Rock Mechanics Symposium.