Authors: Cancino, C; Fuenzalida, MA; Kamp, C

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Cancino, C, Fuenzalida, MA & Kamp, C 2022, 'Modelling considerations for cave compaction at New Afton Mine', in Y Potvin (ed.), Caving 2022: Proceedings of the Fifth International Conference on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 573-582,

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New Afton is a block caving mine located 10 km outside of Kamloops, British Columbia, Canada. The mine operates two lifts, Lift 1 and B3, with two separate caves on Lift 1, the West Cave (WC) and the East CaveĀ (EC). Lift 1 and B3 production levels are located approximately 600 m and 760 m below the ground surface. New Afton has a unique combination of geometric geotechnical conditions when compared to other cave mines, including: 1) a narrow and long footprint; 2) faulted and poor ground areas; and 3) a high horizontal induced stress environment. During mining of the EC, where a majority of the poor rock mass conditions exist, after the cave was propagated through to surface, local areas of the footprint experienced severe damage and high tunnel convergence, which led to some areas being difficult to access and routinely mine. Because of this, the caved and fragmented material located on top of these drawpoints has experienced a high degree of caved rock compaction over time. New Afton was able to successfully rehabilitate much of these areas while observing compacted cave material, but in addition, a Front Cave Recovery Level (FC) was designed 20 m below a section of the EC production level with the purpose of mining the reserves below and recovering supplemental reserves left by the drawpoints. Cave propagation within compacted cave material requires additional consideration when being used in modelling. A methodology to consider compaction within the EC was proposed using the IMASS model. Assuming two different degrees of compaction for the pre-existing EC, the FC was then assessed with a coupled modelling approach using FLAC3D and REBOP to simulate both the draw/flow and caving propagation to determine abutment stresses and cave loads induced on the production level as material was drawn. It was found that having different degrees of compaction significantly affected the predicted caving rate and cave geometry, affecting ultimate recovery.

Keywords: numerical modelling, cave compaction, cave propagation, Front Cave, recovery level

Agapito Associates Inc. 2018, Determination of horizontal principal stresses using the downhole overcoring method at the New Afton Mine, Kamloops, British Columbia, technical report prepared for New Gold.
Castro, R 2006, Study of the Mechanisms of Granular Flow for Block Caving, PhD thesis, The University of Queensland, St Lucia.
Fuenzalida, MA, Pierce, ME & Katsaga, T 2018, ‘REBOP–FLAC3D hybrid approach to cave modelling’, in Y Potvin & J Jakubec (eds), Caving 2018: Proceedings of the Fourth International Symposium on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 297–312,
Fuenzalida, MA & Pierce ME, 2019, Extraction Level Stability Analysis: B3 Cave, presentation delivered to New Afton Mine.
Janssen, HA 1895, ‘Getreidedruck in Silozellen’ (Grain pressure in silo cells), Zeitschrift des Vereines Deutscher Ingenieure, vol. 39, pp. 1045–1049.
Ghazvinian, E, Garza-Cruz, T, Fuenzalida, M, Bouzeran, L, Cheng, Z, Cancino, C & Pierce, M 2020, 'Theory and implementation of the itasca constitutive model for advanced strain softening (IMASS)', ARMA 54th US Rock Mechanics/Geomechanics Symposium, American Rock Mechanics Association, Golden.
Hoek, E & Diederichs, M 2006, 'Empirical estimation of rock mass modulus', International Journal of Rock Mechanics and Mining Sciences, vol. 43, pp. 203–215.
Itasca Consulting Group, Inc. 2019, FLAC3D - Fast Lagrangian Analysis of Continua in Three Dimensions, version 7, computer software, Itasca, Minneapolis.
Kamp, C 2022, ‘Management of production drift convergence and re-development’, in Y Potvin (ed.), Caving 2022: Proceedings of the Fifth International Conference on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 825–842.
Kwok, CY & Pierce, ME 2011, 'Time-dependent compaction in caving rock', ARMA 45th US Rock Mechanics/Geomechanics Symposium, American Rock Mechanics Association, Golden.
Laubscher, D, Guest, A, Jakubec, J & Chitombo G 2017, Guidelines on Caving Mining Methods, The Underlying Concepts, W.H Bryan Mining and Geology Research Centre, St Lucia.
Lorig, L 2000, ‘Relation between caved column height and vertical stress at the cave base’, ET Brown (ed.), report, Julius Kruttschnitt Mineral Research Centre, Indooroopily, and Itasca Consulting Group, Inc., Minneapolis.
Lorig, LJ & Varona, P 2013, 'Guidelines for numerical modelling of rock support for 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. 81–105,
New Afton Mine 2016, Section 6, Rock Properties, technical report MIN-PLAN S204, GCMP.
Stewart, D, Rein, R & Firewick, D 1984, ‘Surface subsidence at the Henderson Mine’, Geomechanics Applications in Underground Hardrock Mining, WG Pariseau (ed.), Society of Mining Engineers, New York, pp. 205–212.
Pierce, ME 2010, A Model for Gravity Flow of Fragmented Rock in Block Caving Mine, PhD thesis, The University of Queensland,
St Lucia.
Pierce, ME 2013, 'Numerical Modeling of Rock Mass Weakening, Bulking and Softening Associated with Cave Mining', ARMA email newsletter vol. 9, viewed March 3, 2020,

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