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2014WinShotcreteEMag

As part of the program of research to develop the application of high-quality shotcrete with no high-performance economical shotcrete, several disruptions to the successful production ramp-up trials were undertaken by Newcrest and shotcrete of the Cadia East Project. consultant Technologies in Structural Engineering Pty Ltd (TSE), including: References • Investigating the influence of air-entraining 1. Duffield, S. B.; Singh, U.; and Bernard, E. S., agent, microfibers, and silica additives on “Economical Mix Design Enhancements for FRS,” 3rd the wet properties and early-age strength International Conference on Engineering Developments in characteristics of fiber-reinforced shotcrete1; Shotcrete, Queenstown, New Zealand, CRC Press/Balkema, • In-place testing of fiber-reinforced shotcrete the Netherlands, Mar. 2010, pp. 85-98. 2. Bernard, E. S., “Point-Load Testing of Macro-Synthetic load capacity and failure modes2; and Fibre Reinforced Shotcrete Linings in the Cadia Hill Vent • Testing of mine waste rock as shotcrete Adit,” TSE Report 221, NML Internal Report, May 2011. aggregate. 3. Lett, J. L., and Emmi, J., 2010, “The Use of Geotechnical As an independent laboratory accredited by Photogrammetry in Underground Mine Development,” 3rd NATA for public testing services, TSE have also International Conference on Engineering Developments in Shotcrete, Queenstown, New Zealand, CRC Press/Balkema, carried out specialized testing for Cadia East. the Netherlands, Mar. 2010, pp. 181-189. The Cadia East Project has also offered the opportunity to trial photogrammetry to measure applied shotcrete thickness. A heading is digitally captured post-scaling and post-shotcreting and Stephen Duffield is a Project measurement of shotcrete thickness and coverage Manager at Newcrest’s Cadia is undertaken with the photogrammetry software. Valley Operations, situated near Cross-referencing of thickness measurements Orange, NSW, Australia. He from drill holes showed an accuracy of ± 0.2 in. received his BSc (Eng) in Mining (± 5 mm).3 Engineering from Cardiff Uni- Further innovation has taken place with the versity, Wales, UK, in 1984, and bulk delivery of set accelerator. An 8000 gal. recieved a degree in project (30,000 L) bulk storage tank and delivery system management from the University of Sydney, Sydney, supplied by BASF was commissioned in May Australia, in 2003. Duffield has worked in under- 2013. This reduces the need for multiple 260 gal. ground mining, construction, and tunnelling on (1000 L) intermediate bulk containers or “palle- both the contractor and client sides. He holds an cons,” which can be damaged in the underground NSW Underground Mine Manager’s Certificate. environment. This innovation has reduced the Duffield has been involved with shotcrete on deep frequency of deliveries to site and given the added mining projects since 1992 and has published six benefit of improved costs. shotcrete-related papers. He is a committee member of the Australian Shotcrete Society. Summary The sheer size and complexity of the Cadia The Outstanding East Project have made the application of fiber- International Project reinforced shotcrete a significant challenge. The combination of depths of up to 4600 ft (1400 m) Project Name underground, distances from surface batch plant Cadia East Project to spraying sites of over 6.2 miles (10 km), the need to spray multiple headings in-cycle, and the Project Location interaction with mining and construction mobile Orange, NSW, Australia equipment accessing through one main decline, Shotcrete Contractor has been an incredible test of design, logistics, Stratacrete Pty Ltd and resource organization. At Cadia East, fiber-reinforced shotcrete is Architect/Engineer essential for the safe development of a world-class Cadia Valley Operations (Newcrest Mining Ltd) mining project—without the application of con- Material Supplier/Manufacturer sistent, high-capacity shotcrete on time and in the Boral Concrete & Quarries Pty Ltd right locations, the project would stop. A key Elasto Plastic Concrete Pty Ltd factor in the successful application of shotcrete BASF Australia Ltd has been the willingness of all teams involved, whether contractors, suppliers, consultants, or the Project Owner client, to work together, seek high performance, Newcrest Mining Ltd and value innovation. These values have ensured Shotcrete • Winter 2014 21


2014WinShotcreteEMag
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