Construction
The 6.8 kilometre Clem Jones Tunnel (CLEM7) is one of the largest infrastructure projects ever to be undertaken in Queensland.RiverCity Motorway has contracted the design and construction of the tunnel to the Leighton Contractors and Baulderstone Hornibrook Bilfinger Berger Joint Venture (LBB JV).Construction of the $3 billion toll road in commenced in September 2006. There are now more than 1,500 people working below the city streets.
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Tunnelling is well under way at the project’s three tunnel worksites. Tunnelling 4 kilometres from Bowen Hills to Woolloongabba, the project’s two tunnel boring machines are successfully digging through Brisbane’s hard rock.
With a 12.4 metre diameter and a body that is more than 250 metres long, the tunnel boring machines are the largest of their type in the world. The machines operate like a moving factory, excavating the rock, erecting the concrete tunnel lining and placing the road base as they go.
The excavated rock is removed from the tunnel via an enclosed conveyor and stored in large silos before being loaded on to trucks and transported off-site.Operated by a team of 22 people per shift, the machines will excavate 75 percent of the tunnel.
Eight roadheader machines working on the south side of the Brisbane River are completing the remaining tunnel excavation.Roadheaders, each weighing up to 135 tonnes, are well advanced at Kangaroo Point creating the entry and exit ramps for the future connection to Brisbane’s eastern suburbs. At Woolloongabba, 900 metres of tunnel is being excavated as roadheaders excavate south towards the Pacific Motorway, and east to the southern ventilation station.
Woolloongabba is also the final destination for the tunnel boring machines. When they reach Woolloongabba in mid 2009, the machines will be dissembled underground and removed via a purpose built access shaft.
Bridge construction and road widening
Above the ground, bridge construction and road widening is well advanced.Work has started on all of the 18 bridges being constructed, or widened, at either end of the tunnel. 11 of these bridges are already substantially complete.
In March 2008, the project reached another major milestone when the first section of the tunnel’s northern interchange was opened to traffic. This bridge gives motorists improved connectivity by providing a direct link from the Inner City Bypass to Lutwyche Road.
Major road widening work is continuing at the northern, eastern and southern entrances to the tunnel. This work will ensure motorists enjoy fast, safe and reliable access as they enter and exit the tunnel.
Fast facts
Tunnel
| Length | 4.8 kilometre twin, 2-lane tunnels |
| Rock to be excavated | 3.5 million tonnes |
| Tunnel lining segments | 38,000 |
| Concrete | 280,000 cubic m |
Tunnel boring machines
| Cost | A$50 million per machine |
| Diameter | 12.4 metres |
| Length | 253m |
| Weight | 4,000 tonne |
| Cutters | 78 tungsten carbide tipped 19 inch disc cutters |
| Manufacturer | Herrenknecht (Germany) |
| Progress | Up to 20 metres per day |
| Crew | 22 people per shift |
Bridges
| Total number of bridges | 18 |
| Number of beams | 350 Super T bridge beams |
| Length of beams | 25 kilometres if placed end-to-end |
| Number of decks | 1,100 |
| Biggest beam | 39 metres long and weighs 75 tonne |