Buried end for Airport Link TBMs Jan 2011
BrisConnections Progress Report
Some 17km of TBM, roadheader and cut-and-cover tunnelling comprises the Airport Link highway
- The two 12.48m diameter TBMs working on the Airport Link highway in Brisbane are destined never to see daylight again. When they reach the end of their 2.5km long journeys later this year, they will be lowered into pits in the invert in the roadheader sections of the tunnels into which they junction, rather than being lifted to the surface. The decision avoids a 50m deep reception-recovery shaft near Chalk Street in the residential area of Lutwyche and bypasses about three months of surface work and a large work shed at the site needed to shield the community from construction noise, dust and disruption.
- The two 12.48m diameter Herrenknecht TBMs started tunnelling from the working site in Toombul in July 2010 and were about 500m into their respective 2.5km long drives by the end of December 2010. Later in 2011, the two machines are expected to break into junction chambers at the end of the roadheader sections of the tunnels being advanced from the Bowen Hills and Kedron work sites to the southwest. With a diameter of 12.48m the cutterheads and shields are wider than the completed TBM or roadheader tunnels and will remain underground and buried in 14.5m x 14.5m x 16.5m deep pits excavated in the invert of the junction chambers. With a combined investment of $45 million, the main components of the machines and their 180m long trailing backups will be withdrawn back through the drives to the Toombul working site.
- "After dismantling the components and backups, the hydraulic systems and gearboxes of the shields will be drained and capped before being lowered onto prebuilt cradles and backfilled with concrete," explained Gordon Ralph, Project Director for
Early 2011 Fast Facts: More than 60% of construction complete More than 13.5 million hours worked More than 3,700 people are working across the project More than $2 billion spent More than 80% of all earth works and tunnelling excavated Mechanical and electrical fit out of the completed roadheader tunnels underway 17 roadheaders being used on the project, the largest number on any Australian project Largest TBMs ever used in Australia Weight - 3,600 tonnes; Length – 195m Cost - $45 million for both Took 12 months to build and a further 3 months to assemble at Toombul. Cutterheads dressed with 80 x 17 inch cutters 22 workers in each TBM operating crew Tunnel alignment about 55m below ground surface Lined with rings of precast concrete segments
- the Thiess John Holland construction JV. "Burial of machines is a common practice around the world and reduces the complexity of removing the cutterheads and shields. Holes will be cut into sections of the shields to ensure complete internal and external encasement of the machines in concrete."
- When it opens in mid-2012, the 6.7km Airport Link toll road will improve travel times between the city and the airport, providing six new lanes for drivers from Bowen Hills and Kedron and four new lanes between Kedron and Toombul. Design-build construction of the tunnels by the Thiess John Holland JV, is part of a massive $4.8 billion infrastructure investment on Brisbane's Northside which includes the Northern Busway tunnel between Windsor and Kedron as part of the Thiess John Holland contract.
- To date, more than 8km of the 15km of TBM, roadheader and cut-and-cover tunnelling needed across the project is completed. This includes finish of the 490m of roadheader excavation for the Northern Busway tunnel.
- In mid-October 2010, Aker Wirth reported that one of its four heavy-duty T3.20 roadheaders working on the project broke through to finish excavation of the 490m Busway tunnel at Lutwyche. All four machines are equipped with 300kW powered inline cutterheads and have an operating weight of more than 130 tonne.
- The roadheaders are operating in different sections of the Airport Link tunnel project, successfully facing the specific challenges of each section. With local support as and when required, and a full complement of consignment stock on site in Brisbane, Aker Wirth has ensured a smooth operation of the machines and low maintenance downtime.
- For Brisbane, road tunnelling will continue once the Airport Link is completed. Just as the Airport Link project continues from the finish of the CLEM 7 toll tunnel under the Brisbane River, so the Northern Link project will continue from the finish of the Airport Link. Following that a further highway tunnel and a proposed cross city underground railway services is being considered to improve traffic and public transportation services around the rapidly expanding metropolis.
Brisbane road tunnels survive flood threat - TunnelTalk, Jan 2011
TBM launch for Brisbane Airport Link - TunnelTalk, August 2010
Brisbane's Airport Link powering ahead - TunnelTalk, June 2010
Brisbane awards Northern Link highway - TunnelTalk, Sept 2010
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