Winner of the R.W Hawken Award for the most prestigious project of the 2014 Queensland Engineering Excellence Awards, TrackStar Alliance has set a new standard in rail infrastructure with the Queensland Government’s $360 million Richlands to Springfield project.
The partnership between Thiess, AECOM, Aurecon, Queensland Rail and the Department of Transport and Main Roads delivered the landmark project on time and under budget – an impressive result considering the scope included 9.5km of dual-track passenger rail line, two new stations, seven rail bridges, more than 1.5km of elevated rail structures and a 5.5km highway upgrade.
Central to the team’s approach was a willingness to challenge the reference design to meet all functional requirements while creating significant savings. The optimised viaduct design showcases the strength of TrackStar’s strategy. Supported by critical realignments to local road infrastructure, the team achieved a flatter and simpler viaduct structure that was 5m lower than the reference design, with a dramatically reduced length of 815m, down from 918m.
The design minimised work at heights during construction and increased the operational maximum design speed by 20km/h to 140km/h. In areas such as the embankment and capping designs, the team developed alternatives based on actual site conditions.
Strategies such as proving the ability to safely remove outer verge layers on certain embankments, supported by a program of in-situ testing during construction, led to significant material and time savings.
Leading into Springfield Central Station, back-to-back cross-overs eliminated more than 900m of track work, while the station itself features a 12m-wide island platform that will accommodate population growth and a future seven-car train set. Close collaboration with government planners meant that TrackStar’s optimised design also removed almost 100 per cent of redundant rail and road work by accommodating long-term regional plans.
The state-of-the-art Springfield Central Station – the project’s centrepiece – is one of Queensland’s most impressive and unique rail stations, featuring a spacious arched structure. Integrating all transport modes, passengers enjoy a completely sheltered journey between rail and bus through the careful positioning of bus shelter roofs, a protected yet light concourse, and a fully enclosed platform core.
The platform canopy design is unique in Queensland for an elevated station, overcoming passengers’ increased weather exposure resulting from the station’s elevation. The design adjusts the level of weather protection throughout the shelter based on predicted passenger concentrations. Constructing the landmark station was a major undertaking, with the station platform and track support structure consisting of 13 identically cast, 20m-wide, in-situ arches.
The team developed an innovative, custom-made, traveling formwork system that reduced the original five soffit forms down to two, reduced forms by 70 per cent and formwork crews by 50 per cent, and cut cranage by 66 per cent. The soffit forms could be moved from one arch to the next within minutes, significantly reducing costs, improving cycle times and enabling better safety outcomes.
Another innovation during construction was the design of a new, purpose-made, self-supporting steel formwork box to construct the 26 headstocks needed to deliver the 815m-long viaduct. At a minimum height of 16m each, they were prefabricated off-site, lifted in one piece onto completed columns, supported and fixed down, and then suspended from bridge piers.
A reduction in labour requirements and costs, and an improvement in cycle times, this innovation ultimately brought 300 man-hours of work at heights back down to earth – a major safety advantage. The Richlands to Springfield project is the most significant new rail infrastructure to Queensland Rail’s suburban Brisbane network in 30 years.
Article and image supplied by TrackStar Alliance
