New access drives for mighty mine operation Sep 2011
Shani Wallis, TunnelTalk
- After a protracted procurement process, Codelco has awarded a contract for the new access tunnels into its El Teniente copper mine in Chile to Vinci of France.
- Through its subsidiaries VINCI Construction Grands Projets (60%) and Soletanche Bachy (40%), VINCI will complete a US$400 million contract to design and build two 9km long access tunnels into a new ore deposit at the world's biggest underground copper mine high in the Chilean Andes.
- The contract covers drill+blast of twin 9km tunnels, each with an average cross section of 65m2, plus two intermediate access tunnels totalling 6km. The first of the main tunnels is for bus transportation of mine personnel. The other is for haulage of ore.
- Seven international groups prepared design-build proposals for the design-build, cost-reimbursable incentivised contract. Reference design and contract documentation for the design-build project was prepared by design engineer Hatch Chile, in conjunction with tunneling staff from Hatch Mott MacDonald in Canada/USA and Mott MacDonald in the UK.
Codelco's El Teniente operations are high in the Chilean Andes
- El Teniente is located at an altitude of between 1,500m and 1,900m, some 80km to the south of Santiago, in the Libertador General Bernardo O'Higgins region in the Andes. The new mine level project will extend the life of the mine by 60 years and maintain the mine's production at its tremendous 137,000 tonne/day.
- Geological conditions comprise mixed bedrock ranging from strong volcanic deposits to highly altered and weak rock with fault zones. A ground reference conditions report (GRR) was compiled for possible drill+blast or TBM excavation.
- According to a statement by Vinci, works are scheduled to start next month (October 2011) and take 40 months to complete.
- Current Vinci contracts for underground works include the Hallandsås rail tunnels in Sweden, the Liefkenshoek rail tunnel in Belgium, the Cairo metro in Egypt and the Brightwater tunnel project in the USA. Ground technologies specialist Soletanche Bachy has been operating in Chile's mining sector for many years and is in joint venture with Vinci and Morgan Sindall on the large diameter Lee sewer tunnel in London.
Chilean mine invites access project - TunnelTalk, Nov 2009
Hallandsås celebrates first tunnel finish - TunnelTalk, Aug 2010
Convertible EPBM heading for Cairo Metro - TunnelTalk, Sept 2009
Two Brightwater TBMs hole through - TunnelTalk, June 2010
TBM commissioned to tackle London CSO task - TunnelTalk, May 2011
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