People who know tunnelling
Walter Mining's staff have considerable experience with tunnelling technologies being intimately involved in the following civil and multi-disciplined underground projects over the past decade:
Smoothing traffic flow in fast growing cities
The Sydney Harbour Tunnel was completed in 1992 and is a proven and integral part of connecting Sydne's road users by smoothing traffic flow across our beautiful harbour. Our experience portfolio for this complex, multi-disciplined underground project (from the southern shore) included hard rock excavation by roadheaders, sequential method of excavation for work under the forecourt of the Opera House and complex staging of work to join the land tunnels to the immersed tube tunnels laid across Sydney Harbour.
And the M5 East Motorway – this project included roadheader excavation for half of the total length of driven tunnels.
Rail projects too… helping commuters get there
To improve the Brisbane Rail Network, two separate projects from Roma Street to Central Station and from Brunswick Street to Central station both used sequential excavation methods with low ground cover under the Brisbane CBD.
Services infrastructure - Water and Waste-water tunnel projects
In the Illawarra region the Illawara Water Treatment Plant Tunnel was driven from the Illawarra escarpment to beneath the Avon Dam. This tunnel was connected to the dam by way of a 100m raisebore.
Bondi RIAMP upgrade – via an alliance with Sydney Water and three other companies we worked in a consortium team to upgrade the Bondi underground treatment facility including roadheader excavation work to facilitate installing overall capacity upgrade.
Using a 3.3m diameter tunnel boring machine (TBM) for three kilometres and roadheaders for the last 500m of driveage, an access tunnel was built for Transgrid under Sydney by the team who now operate Walter Mining's tunnelling project team.
Innovative gas storage solution
Elgas engaged Walter Mining to deliver four interconnected gas storage caverns. These were excavated at a level of 140 metres below the surface to provide a sophisticated subterranean gas storage facility. Each cavern is 140 metres long, 11 metres high and 13 metres wide. Access was gained by two shafts – one for men and materials and one for muck disposal. Water curtain galleries were driven above the main caverns from where major drilling works enabled water injection into the rock surrounding the caverns thus providing a water seal under pressure around the gas storage system.
Project management to deliver on time solutions
Walter Mining has both the practical tunnelling operators and equipment, plus the engineering and proven management systems to provide on-time tunnel delivery. Our safety practices ensure high productivity and low OHS outcomes as we operate at eight times below the usual industry standards for lost time due to injury.