Saunders, E, LeRiche, A, Shapka-Fels, T & Barnett, W 2020, 'Characterisation of foliated rock masses using implicit modelling
to guide geotechnical domaining and slope design', in PM Dight (ed.), Proceedings of the 2020 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering
, Australian Centre for Geomechanics, Perth, pp. 535-550, https://doi.org/10.36487/ACG_repo/2025_32
The stability of rock slopes designed and excavated within anisotropic rock masses are influenced by several factors, some of which include spacing intensity, continuity, roughness, dip and dip direction, and waviness. Foliation-parallel instabilities are often expressed at the multi-bench or inter-ramp scale due to the high persistence, larger-scale dilation and breaking of intact rock bridges. Functional pit slope designs need to account for the variability in foliation character with consideration to the mining geometries being developed.
The accepted approach is to partition the rock mass into three-dimensional (3D) geotechnical domains to reduce complexity for slope design guidelines. Inputs guiding the development of the geotechnical domains can either be from highly manual interpretations, which are tedious and coarse in resolution, or implicit 3D foliation modelling methods. To demonstrate this, implicit models, such as form interpolants and/or block models, were first used at Jwaneng mine and have subsequently been generated and used to inform domaining and design at two operating mines (Rainy River and Rosebel Gold mines) and one other project site. The models were developed from different sources of geotechnical/geological data (i.e. oriented drillhole logging, televiewer, grade cutoff, pit face and photogrammetry mapping). The validation of the models has been further investigated with techniques presented in this paper.
Keywords: rock mass fabric, kinematics, geotechnical risk, pit design, bench performance, implicit modelling
Bar, N & McQuillan, A 2018, ‘3D Limit Equilibrium Slope Stability Analysis for Anisotropic and Faulted Rock Masses in Australian Coal and Iron Ore Mines’, Proceedings of the 10th Asian Rock Mechanics Symposium, International Society of Rock Mechanics, Singapore,
Creus, PK, Basson, IJ, Koegelenberg, CK, Ekkerd, J, de Graaf, PJH, Bester, M & Mokele, T 2019, ‘3D Fabric Analysis of Venetia Mine, South Africa: Using Structural Measurements and Implicitly-Modelled Surfaces for Improved Pit Slope Design and Risk Management’, Journal of African Earth Sciences, vol. 155, pp. 137–150.
Hencher, SR, Lee, SG, Carter, TG & Richards, LR 2011, ‘Sheeting joints: characterisation, shear strength and engineering’, Rock Mechanics and Rock Engineering, vol. 44, issue 1, pp. 1–22.
Murphy, B & Barnett, W 2018, ‘Approach to Geotechnical Characterization and Slope Design Data Acquisition Programs In Different Deposit Types’, Proceedings of the 2018 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering, Asociacion Nacional de Ingenieros de Minas, Seville, pp. 1315–1329.
Passchier, CW & Trouw, RAJ 2005, Microtectonics, Springer Science & Business Media, Berlin.
Seequent 2019, LeapfrogGeo™, version 5.0, computer software, Seequent, Christchurch.
Stead, D & Wolter, A 2015, ‘A Critical Review of Rock Slope Failure Mechanisms: The Importance of Structural Geology’, Journal of Structural Geology, vol. 74, pp. 1–23.
The University of the State of New York 2011, Reference Tables for Physical Setting/Earth Science, Albany, New York,
Thomas, RDH, Neilsen, JM, Wilson, HF & Lamb, P 2015, 'Structural interpretation from Televiewer surveys', in PM Dight (ed.), Proceedings of the Ninth Symposium on Field Measurements in Geomechanics, Australian Centre for Geomechanics, Perth, pp. 729–74.
Zorzi, L, Massironi, M, Surian, N, Genevois, R & Floris, M 2014, ‘How Multiple Foliations may Control Large Gravitational Phenomena: A Case Study from the Cismon Valley, Eastern Alps, Italy’, Geomorphology, vol. 207, pp. 149–160.