Northparkes Mines is a joint venture between Rio Tinto and the Sumitomo group and is operated by Rio Tinto to produce copper concentrate from ore sourced from open cut and underground._x000D_
Underground ore is mined with an owner operator workforce using the block cave method from the E26 deposit, with the first lift of the cave now completed. Development of the Lift 2 block cave commenced in March 2001 using a contract workforce._x000D_
The Lift 2 Project required the mining of 14 700 m of decline and lateral development to establish a new mining horizon at the 9450 level and to develop two new conveyor declines._x000D_
Also included in the scope was the excavation of a Crusher chamber to house the jaw-gyratory crusher._x000D_
This paper describes the excavation of the hydroset chamber and orepass that sit immediately underneath the Lift 2 Crusher chamber. It includes risk assessment, planning, development of method statements and standard operating procedures, through to the excavation of the orepass and the installation of ground support in seismically active ground._x000D_
There was a major ground failure in the backs of the conveyor feeder chamber during its excavation, which affected the excavation of the orepass due to its proximity to the breakthrough site._x000D_
FORMAL CITATION:Nixon, J and Westo, A, 2005. Excavation of the lift 2 crusher hydroset chamber and orepass in seismically active conditions at Northparkes Mines, in Proceedings Ninth Underground Operators' Conference 2005, pp 193-202 (The Australasian Institute of Mining and Metallurgy: Melbourne).