Ghazvinian, E, Orrego, C & Fuenzalida, M 2023, 'Numerical forecast of central access ground support behaviour at Cadia East PC1-2', in J Wesseloo (ed.), Ground Support 2023: Proceedings of the 10th International Conference on Ground Support in Mining, Australian Centre for Geomechanics, Perth, pp. 521-534, https://doi.org/10.36487/ACG_repo/2325_35
(https://papers.acg.uwa.edu.au/p/2325_35_Ghazvinian/)
Abstract: The future PC1-2 block cave at Cadia East considers a central access to allow for a unique material handling system made up of two crusher chambers located at the northern and southern ends of the footprint. To implement this solution, a row of drawbells was removed from the mine design in the centre of the footprint, which creates a geotechnical singularity with the potential to be affected by increasing cave loading due to less interactive drawing on top of the central access, resulting in a stagnant zone formed above the drive. This stagnant zone is likely to attract stresses. This, in combination with the complex geometry of the super apices above the central access, increased the focus on long-term stability and the adequacy of the proposed ground support design; therefore, it was assessed using bonded block model (BBM) modelling with explicit ground support.
A BBM analysis was carried out to forecast support behaviour by explicitly representing the planned ground support in the model and its impact on the stability of the central access drive. The models simulated the process of excavating the drive, support installation, abutment loading and unloading, and lastly, cave loading to assess excavation stability and rock mass response in the vicinity of central access through the life of mine. This paper summarises the analysis, assumptions and outcomes of the study.

Keywords: ground support, cave loading, bonded block model, forecast support behaviour