Forrestfield-Airport Link milestone: tunnel lining production complete
PERTH, 12 April, 2019 - Salini Impregilo has produced the last of the 54,000 segments and reached a significant milestone for the Forrestfield-Airport Link, finishing the production of the precast concrete segments that line the walls of the parallel tunnels being excavated for the rail line in Perth, Australia.
A purpose-built factory was established for the project, with a concrete batching plant, a carousel line and a steam curing chamber operated by Boral Ltd, a concrete supplier.
A world-class operation, the factory has set the standard for tunnel construction in Australia. The segment moulds were designed specifically for the project. Each segment has a double gasket, is water tight and has a durability of 120 years. The concrete mix was formulated according to specification, incorporating steel and polypropylene fibres to enhance strength and fire resistance. Close attention was given to the environment. In the formulation of the concrete mix, 20% of the steel fibres came from recycled material. After the production of each segment, the concrete waste material from the wet and dry concrete bins was converted into road-base or drainage rock.
Once completed by Salini Impregilo and its joint-venture partner NRW Pty Ltd, the Forrestfield-Airport Link will deliver an 8.5 kilometre extension to the existing rail network, spurring off the Midland Line just past Bayswater Station and running though twin-bored tunnels to the eastern suburb of Forrestfield. It will have three new stations, one of them at the airport.
By 2021, it is expected to generate 20,000 passenger trips on the network every day, helping reduce road traffic, commuting times and air pollution.