Singh, U, Dixon, RA & McArthur, C 2010, 'Interaction between a propagating cave and an active pit at Telfer Mine — Part I: interaction management', in Y Potvin (ed.), Caving 2010: Proceedings of the Second International Symposium on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 307-320, https://doi.org/10.36487/ACG_rep/1002_21_Singh (https://papers.acg.uwa.edu.au/p/1002_21_Singh/) Abstract: The Telfer Underground Sublevel Cave (SLC) Operation is located approximately 800 m below the West wall of the Main Dome Open Pit. The Telfer SLC initiated in late 2006 and is caving successfully at a global rate of approximately 0.6 m per day. The cave is expected to break into the planned 5384 bench on the West wall of the active Main Dome pit which has a haul ramp running along the wall at approximately 70 m horizontal distance from the edge of the cave. The breakthrough area of the pit was being mined as the cave was propagating, requiring assessment of the potential for rapid propagation and unexpected subsidence. The key trigger points for evacuating and barricading the breakthrough area were based on monitoring of the cave propagation, the calculation of air gap and risk assessment of the interaction. Monitoring of key parameters was critical for informed decision making and safe management of the interaction between the cave and the pit. Part I of this paper discusses the risk management strategy and tactics used for managing the interaction, including implementing a second ramp, preloading the breakthrough area and setting up a major hazard management plan. A trigger, action, and response plan is also used to monitor key parameters, identify predetermined triggers and take the designated action.