The last of 24,000 concrete tunnel lining segments has been cast for New Zealand’s Waterview Connection project.
Each segment, weighing up to 10.5t, is one of 10 which make up 2,414 rings of concrete lining. Each ring is 2m wide and 14m in diameter.
During operation, tunnel boring machine (TBM) Alice has been installing the segments at a rate of six linings every 24 hours.
Brett Gliddon, New Zealand Transport Agency’s Auckland state highways manager said: “The linings for these tunnels have needed to be extremely precise with to-the-millimetre precision so they fit perfectly together inside the tunnels. They’re also incredibly strong, durable enough to withstand 100 years of traffic use.”
The concrete segments are produced by a purpose-built factory in East Tamaki and then delivered to the project site in Owairaka.
Watch the video below for a step-by-step overview of the segment making process:
The East Tamaki facility was built through a partnership between the tunnel project’s Well Connected Alliance and Wilson Tunnelling.
Gliddon added: “The linings have been a key component in the design and construction of the twin tunnels and this factory has done a first rate job consistently delivering such a big quantity on time.
“This has made a significant contribution to keeping us well on target for the project to be completed in December 2016, and the planned opening to traffic in early 2017.”
The Waterview Connection project interchange and tunnels will link the Northwestern and Southwestern Motorways to complete the Western Ring Route.
The East Tamaki pre-cast factory has produced:
- 24,000 tunnel lining segments
- 2,406 culvert units
- 279 bridge beams
Materials used by the factory include:
- 95,000 cubic metres of concrete
- 3,500 tonnes of conventional reinforcing
- 4,500 tonnes of steel fibre reinforcing