Bridge and road construction in Australia is surging, with an injection of public funding and progress on public-private partnership developments expected to push industry revenue in 2024-25 to $41.2 billion.
The recently completed Fitzroy River Bridge and the ongoing Mandurah Estuary Bridge duplication project aim to ease congestion and enhance connectivity at critical river crossings in WA’s regions.
The Fitzroy River Bridge was severely damaged during flooding caused by Tropical Cyclone Ellie in January 2023, requiring a new bridge to reconnect the East and West Kimberley region. Jointly funded by the federal and WA state governments through Disaster Recovery Funding Arrangements, the bridge was delivered by Georgiou and BMD Group, along with design consultant BG&E.
It was recently awarded the WA Project of the Year at the Engineers Australia Excellence Awards, for demonstrating innovative solutions, rapid construction and the effective management of complex challenges.
The award citation added: “The new bridge has provided a vital connection for the community and serves as a testament to the power of engineering to deliver positive outcomes.” The $245-million two-lane bridge was finished last December in just 10 months, more than six months ahead of schedule.
More than 260 locals were employed, with 25 per cent of construction hours worked by Indigenous Australians and 26 Indigenous-owned businesses contracted for a total $34-million spend. WA Premier Roger Cook said losing the Fitzroy River Bridge in January’s devastating floods was a massive blow to communities in the Kimberley, who relied on the vital artery for freight, transport and connection.
Cook said: “To see it built back better and stronger, six months ahead of schedule, and in time for the wet season is a truly remarkable achievement. “It is even more remarkable when you consider the remoteness of Fitzroy Crossing and the unforgiving conditions crews were faced with.” The new bridge was constructed in several key stages to ensure it became operational as soon as possible and to avoid the impacts of the next wet season.
First, a temporary causeway made from locally sourced gravel overlaying stone basecourse was built from the west side of the river, which was required to gain access to the old bridge during demolition and allowed access for machinery while keeping excess water away from the area. The causeway was then extended to the eastern side and pipes installed to allow the river to continue flowing until the causeway was removed.
A 50-tonne excavator was used to demolish the old bridge, with it cut into sections and material collected from site and broken down to be recycled and reused where possible. Booms were used as an environmental measure to ensure debris was not washed down the river during the demolition process.
The first stage of construction – which began while final demolition works were still being completed – involved the installation of steel piles which were then filled with reinforced concrete to hold up the bridge.
A total of 34 piles were driven into the riverbed to support the bridge, with four piles supporting each pier.
As the old bridge’s piles were too shallow to withstand the volume of water experienced during the floods, the new piles extend an extra 20 metres underground.
Pile caps, which are thick concrete blocks, were then placed on top of each grouping of four concrete piles, to create a stable foundation by distributing the entire load of the bridge over the piles.
The piles and pile caps provided a base to build the piers, which each comprised four precast shell segments that were bolted together and placed on top of the piles and pile caps.
Once in place, the precast shell segments – which were prefabricated in Perth – were filled with steel reinforcement and concrete.
Finally, each of the eight bridge deck segments were constructed on the concrete casting bed and incrementally launched across the river from west to east.
This was the first time Main Roads WA had used weathering grade steel for a major bridge, with its major benefit being the reduced ongoing maintenance required.
Georgiou Group was also recently awarded the design and construct contract for the Mandurah Estuary Bridge duplication project for Main Roads WA, which is expected to be complete by late 2025.
The $136-million project includes construction of a second two-lane bridge on the south side of the current bridge in Mandurah, 70 kilometres south of Perth, along with a new four- metre-wide shared path to improve connectivity for the local community.
Georgiou General Manager Simon Welfare said Georgiou had demonstrated expertise in constructing bridges in Western Australia, including the design and construction of the award- winning Mandurah Traffic Bridge completed in 2018.
Welfare said: “Building upon our strong portfolio of work with Mains Roads Western Australia, the design and construct contract will be delivered in collaboration with principal designer BG&E, and long-term marine works subcontractor, Brady Marine & Civil.
“We look forward to delivering this critical piece of infrastructure for the Western Australian state and local community.”
The upgrade will not only improve safety, but reduce travel times for the more than 33,000 daily users of the existing Mandurah Estuary Bridge.
Notably, the project includes a provision for a third lane in each direction, giving both bridges the capacity to transition to a three-lane configuration in the future as population and traffic demand grows.
Georgiou General Manager Simon Welfare said Georgiou had demonstrated expertise in constructing bridges in Western Australia, including the design and construction of the award- winning Mandurah Traffic Bridge completed in 2018.
Welfare said: “Building upon our strong portfolio of work with Mains Roads Western Australia, the design and construct contract will be delivered in collaboration with principal designer BG&E, and long-term marine works subcontractor, Brady Marine & Civil.
“We look forward to delivering this critical piece of infrastructure for the Western Australian state and local community.”
The upgrade will not only improve safety, but reduce travel times for the more than 33,000 daily users of the existing Mandurah Estuary Bridge.
Notably, the project includes a provision for a third lane in each direction, giving both bridges the capacity to transition to a three-lane configuration in the future as population and traffic demand grows.
Construction began in January, with preliminary earthworks and drainage completed and piling for the bridge piers currently underway.
The construction method was also used on the Mandurah Traffic Bridge and Mooro-Beeloo Bridge in Ascot, and will involve bridge segments being constructed at the casting bed on site and launched across the estuary from the southeast side of the existing bridge.
