TBM RECORDER TBM launch for Brisbane Airport Link Aug 2010
Patrick Reynolds, Freelance Reporter
- A year-long drive has begun for Rocksy, the first of two TBMs working on the Brisbane Airport Link. Before the end of this month (August 2010), the second machine, Sandy, is due to set off on the parallel 2.5km highway tunnel bore.
Twin Aiport Link TBM sets off
TBM 2 ready for launch
- Sandy, the second TBM on the Brisbane Airport Link has been launched to follow its sister, Rocksy, for project contractor, the JV of Thiess John Holland.
- The 12.48m diameter Herrenknecht EPB shield is driving the parallel, 2.5km long westbound tunnel for the toll road link.
- The first machine launched at the end of last month (July 2010) is already more than 100m into its drive and has built more than 53 rings.
- Each shield is being launched in a two-stage process requiring some weeks of stoppage after about 130m of progress to complete the assembly. A 1.8km long overland conveyor is being used as part of the spoil removal system behind each TBM.
- The 12.48m TBMs are supplied by Herrenknecht to the Thiess John Holland JV to help excavate part of the new highway project. Almost a dozen roadheaders are also employed on the scheme to open access adits, ramps and various other tunnel reaches and chambers.
- The TBMs are being launched in a two-stage process with about 130m being bored by each machine before being stopped for six weeks for their full backup to be assembled. For Rocksy, this would see boring resume by late September or early October. Each machine is to programmed to advance by up to 85m per week per machine at peak.
- Work on the project started in early 2009 with the roadheaders and they have excavated more than 5km of tunnel so far. The first tunnel hole through by a roadheader was in June. The TBMs will complete the tunnel section south from Toombul below Wooloowin to Lutwyche, and are expected to be all done by mid-2011.
- Excavations last year in the Wooloowin area, for part of the mid-route access ramps and cavern junctions, found weaker ground than expected. Permission was obtained from the owner for a construction modification to sink an additional 42m deep shaft to catch up the programme and avoid slippage that could impact the TBM and completion schedules.
- Almost 15km of tunnels, including the Northern Busway tunnels and access ramps are being excavated for the project, the principal feature of which is the 5.1km long twin tube tunnel. The Airport Link is part of the city's TransApex plan and will operate as a 6.7km long electronic toll road.
Advance of a roadhead tunnel topheading
- BrisConnections was awarded the 45-year toll road concession two years ago by the Government of Queensland. The Thiess John Holland JV is undertaking the design and construction of the link for the concession under a fixed price, fixed term contract.
- John Holland and Thiess are also part of BrisConnections, along with Macquarie Capital, Arup and PB.
- Operation and maintenance of the toll link is to be undertaken by a separate JV of the Thiess and John Holland service divisions. That fixed price contract is initially for five years from mid-2012 when the scheme is scheduled to come into service.
Brisbane takes delivery of second TBM - TunnelTalk, April 2010
Brisbane's Airport Link powering ahead - TunnelTalk, June 2010
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