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Back to SearchOne of the world’s leading engineering, architecture, environmental and construction services companies, GHD, is proud to have helped achieve a first for the Queensland coal mining industry.
A Tunnel Boring Machine (TBM) completed a 1 km long drift (tunnel) for people and equipment for Anglo American’s new Grosvenor underground mine near Moranbah, Queensland. The tunnelling breakthrough came 29 days ahead of schedule.
The TBM previously excavated a 750 m conveyor drift for the mine in six months.
This is the first time an Earth Pressure Balance (EPB) TBM has been used in a coal mining environment in Queensland and one of a few times a TBM has been used in the Australian mining industry. The new method was designed to help Anglo American improve safety, achieve higher quality drifts and expedite project development.
Brendan Henry, GHD’s Tunnel Manager and Principal Engineer, says, “One of the advantages of the EPB TBM is its ability to excavate through weak, water- and gas-bearing ground without exposing workers to these hazards. The TBM reached daily advance rates of 18 tunnel rings, or 25m of fully lined tunnel, driving through minor coal seams charged with methane of pressures above 1.5 Bar. The front section of the TBM was designed as explosion proof to operate in these conditions.”
Anglo American Coal CEO Seamus French congratulated the team at Grosvenor for their outstanding efforts to drive the TBM through the second tunnel significantly ahead of schedule. "This great result is down to the outstanding commitment of the team who came to grips with the new tunnel boring technology last year and applied our operating and engineering experience from underground mining to lift the TBM performance over the last 12 months.”
GHD’s Tunnel Team in Brisbane has been providing tunnelling design and construction phase services for the project since mid-2012 and will continue with site surveillance work throughout the remainder of 2015.
Brendan says, “Our services have included geotechnical investigation and interpretation, tunnel lining design, refuge bay design, conveyor transfer area and underground cavern support design, precast yard and tunnel construction surveillance and full time technical advice on site during tunnelling. The transition from the TBM tunnels into the underground mine workings was designed by GHD utilising a combination of standard coal roof support techniques and 3D analysis due to the large spans and high walls required.”
Brendan concludes, “This is a very exciting project for our team. We are taking design and construction experience from large civil engineering projects into the mining industry, and adapting our skill set to the design of underground coal workings.”