This paper details the events leading up to a slope failure that occurred at Kalgoorlie Consolidated Gold Mines (KCGM) and the remediation method executed using rope access specialists.
n January 2016, KCGM Fimiston Pit experienced a double bench wall failure where approximately 80 000 t of material fell from the wall that blocked access to a ramp and caused minor damage to equipment.
The event was triggered by heavy rainfall and occurred along unfavourable eastward dipping structures that lead into weaker shale/porphyry bands, which in turn left more material on the face. A remediation plan was formulated that would allow for the continuation of open pit operations while a full geotechnical assessment of the failure area could be conducted. This was accomplished by means of rope access specialists who abseiled down the wall and blasted off the remaining overhang using a portable drill rig and prepackaged explosives.
This paper provides a brief overview of the KCGM operations, how the instability was identified and monitored, details of the failure event, outcomes of the geotechnical assessment and details on the remediation work.
Graf, C and Sullivan, R, 2016. The Journey to Steepening the Pit Slope Angle – Advancing the Effectiveness of Wall Control, in Proceedings Ninth AusIMM Open Pit Operators’ Conference 2016, pp 104–114 (The Australasian Institute of Mining and Metallurgy: Melbourne).