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Rapid tunnel/shaft development. M. Cai GRC/MIRARCO, Laurentian University, Sudbury, Canada. Kaiser (2007). The Need for Speed. Many mining companies are converting open-pit to underground operations.
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Rapid tunnel/shaft development M. Cai GRC/MIRARCO, Laurentian University, Sudbury, Canada
Kaiser (2007) The Need for Speed • Many mining companies are converting open-pit to underground operations. • Rio Tinto alone needs to, on average, sink 5 shafts/yr (~1500 m) and develop 80 km of tunnels/yr for the next 12 years. • Mine Construction (Net Present Value (NPV) study of a large mine) • Critical Path Development Critical path construction reduced by 1 yr ΔNPV $73M increased by 1 yr ΔNPV $91M Development cost savings ($1,000/m) ΔNPV $42M • Rapid Tunnel Development Rate increased from 4-5m/d by 25% ΔNPV $ 65M Rate increased by 100% ΔNPV $195M Speed is King
Projects • Boltless support – develop means to rationally assess ground conditions for safe tunnel development under boltless support. • Rock support design and selection rationale – Provide guidelines for cost-effective rock support design in weak and highly stressed grounds. • Rock mass strength at great depth – develop method to correctly assess rock mass strength in deep grounds. • Rapid tunnel/shaft development – develop techniques such as excavation staging and innovative support such as gabion formation and composite support to facilitate rapid tunnel/shaft development. • Going underground – mining and tunneling in weakground • Going deep - mining and tunneling in highly stressed ground • Going faster – rapid tunnel/shaft development
Benefits • For mining companies Multi-kilo-million $ opportunities • For investors/shareholders Good return on investment • For miners Safe work environment • For us (researchers) A great path leading to discovery, contribution to R&D, and professional fulfillment/satisfaction
Partners • Rio Tinto • …… • Collaborator –A • Collaborator –B • …… GRC/ MIRARCO