Establishment of the Cadia East Panel Cave Stage One (PC1S1) commenced with the firing of the first bell in early 2011. Production began with the completion of the undercut in May 2014. PC1S1 used a post-undercut composed of 114 drawbells covering a footprint area of 73 438 m. The extraction level is located at a depth of 1200 m below the surface and is based on a 32_x000D_
20 m El Teniente layout. Cave establishment required the construction of multiple conveyor drifts, a large-capacity jaw-gyratory crusher and ancillary ventilation and pumping infrastructure. Preconditioning via hydraulic fracturing and blasting was implemented at various locations of the cave block height. This paper presents an overview of the key learnings from the commencement of undercutting to surface breakthrough, including rock mass classification and modelling, stress measurements, preconditioning, numerical modelling and cave monitoring.CITATION:Lett, J L, Brunton, I, Capes, G W, Jger, A, Mobilio, B, Rachocki, J, Sharrock, G B and Secheny, M, 2016. Undercutting to surface breakthrough - Cadia East panel cave (stage 1), in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 65-82 (The Australasian Institute of Mining and Metallurgy: Melbourne).