Management of the Kalgoorlie Consolidated Gold Mines East Wall Slip

Authors: Darbritz, J Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2335_47

Cite As:
Darbritz, J 2023, 'Management of the Kalgoorlie Consolidated Gold Mines East Wall Slip', in PM Dight (ed.), SSIM 2023: Third International Slope Stability in Mining Conference, Australian Centre for Geomechanics, Perth, pp. 695-704, https://doi.org/10.36487/ACG_repo/2335_47



Abstract:
In 2018 and 2020, failures in the East Wall of Kalgoorlie Consolidated Gold Mines’ operations in KalgoorlieBoulder, Western Australia, generated a combined ~1.2 Mt of material, causing production delays and loss to the available ore located in the Golden Pike pit below. Back-analysis identified that the Australia East Secondary Splay, the EWD3 Fault and the Fiji Fault formed a wedge that was mobilised by high porewater pressure. The wedge was approximately 180 m in length and 100 m at its widest. In 2021, the plan for mining the slip material via a mine cut back behind the failure started to be developed and implemented. A risk assessment of the in situ wedge left behind found that it could be potentially unstable and thus unsafe to work on top of. A control zone was created using structural data, and additional rockfall protection was built below. The control zone was designated a ‘no feet on the ground’ zone. To manage the project, an area controller role was created to oversee operations and liaise with all stakeholders. This paper will present the methodology adopted to safely mine the first horizontal 40 m of the East Wall Slip from the -150RL to the -190RL. This includes: Specific blasting approaches used. Management of interactions. Rockfall modelling and catchment. Mining methods using a shovel. Use of remote-controlled equipment within the control zone. Monitoring and alarming.

Keywords: slope failure, slope remediation, open pit, cutback mining

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