A sustaining pit-wide geotechnical stability model of Bingham Canyon Mine

Authors: Peik, B; Chamberlain, J; Miller, AK; Lawrence, K; Williams, C; Gaida, M; Morkeh, J; Ergun, S; Gibbs, J; Weigel, J Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2535_32

Cite As:
Peik, B, Chamberlain, J, Miller, AK, Lawrence, K, Williams, C, Gaida, M, Morkeh, J, Ergun, S, Gibbs, J & Weigel, J 2025, 'A sustaining pit-wide geotechnical stability model of Bingham Canyon Mine', in JJ Potter & J Wesseloo (eds), SSIM 2025: Fourth International Slope Stability in Mining Conference, Australian Centre for Geomechanics, Perth, https://doi.org/10.36487/ACG_repo/2535_32



Abstract:
The overall slope stability of Bingham Canyon Mine (BCM) has historically been assessed using multiple 3D wall-scale numerical models of the east, south and north walls of the pit, supplemented by 2D limit equilibrium analyses. The approach resulted in varied assumptions as each model was created during studies that spread across different years, versions of available data and objectives. As the orebody knowledge (OBK) at BCM is continually improving with new data collection, it is necessary that the engineering analyses reflect the most recent characterisation and field observations to support mine planning and long-term design decisions, reduce project uncertainty and eliminate OBK versioning differences between studies. A pit-wide (PW) stability model of BCM was developed to facilitate an improved approach and enhance the efficiency of OBK use in ongoing slope design. Full pit models were historically considered impractical due to computational and resolution limitations, but improved computing technology along with optimised workflows allow for development of a comprehensive PW numerical model that is regularly updated and maintained. The vision for the PW model is to provide a single, integrated representation of current OBK that can be used to inform both operational and mid- to long-term design changes, permitting a straightforward review of underlying assumptions and validation with available slope performance data. Equilibrium Mining and Rio Tinto Kennecott have collaborated to develop the first PW model of BCM, focused on efficient model construction and maintenance, and incorporating detailed back-analysis of the slope response over the past 25+ years. This paper outlines the methodology and key insights from this collaboration and presents an overview of back-analysis of the slope response in the south wall of the pit, demonstrating the value of a unified PW model.

Keywords: slope stability, open pit, numerical modelling, back-analysis, slope movement

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