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A Lasting Legacy

Brisbane's Legacy Way has changed the way tunnels will be built in Australia moving forward.

Brisbane's Legacy Way has changed the way tunnels will be built in Australia moving forward.Over the past year, approximately $9 billion was spent on hundreds of infrastructure projects across Australia. With so many impressive works taking place, it’s challenging to ask which projects stood out from the pack?

In 2015, Infrastructure Partnerships Australia (IPA) is saying that the Legacy Way Tunnel in Brisbane was so outstanding that it deserved The 2015 Project of the Year Award, among a tough crowd of competitors. IPA Chief Executive Brendan Lyon explains to Roads & Civil Works Magazine that for a project to stand out, the independent judging panel that consists of public officials, and this year chaired by Dr. Kerry Schott, looks out for a number of exceptional criteria.

“What the panel asks is what is it that’s really different? What is it that’s world-leading in terms of finance, engineering, technology and construction technique? The Project of The Year has to be something that’s really changed the market,” says Mr. Lyon.

In this space, Mr. Lyon says that Brisbane’s Legacy Way tunnel really does deliver in changing the way Australia will approach tunnelling from herein.

Brisbane City Council contributed $1 billion towards the $1.5 billion project. Brisbane Lord Mayor Graham Quirk said the project would almost halve peak hour travel times between the Western Freeway and the Inner City Bypass at Kelvin Grove.

“As a project, it delivered a number of different technologies that helped reduce costs in the hundreds of millions of dollars,” says Mr. Lyon. “It really brought in a different approach.”

This truly exceptional approach was largely the work of Transcity Joint Venture led by Acciona Infrastructure, along with local contractors BMD Constructions and Italian company, Ghella. For Acciona, a global leader in renewable energy, water, and infrastructure projects, this was the first opportunity the Spain-based company has had to show its development prowess in Australia.

When Brisbane City Council issued a tender for a major tunnel, with a particular focus on opening up the bidding to international companies, Fernando Fajardo, Director of Acciona’s Infrastructure business, tells Road & Civil Works Magazine that the company saw an ideal opportunity. Acciona had identified Australian infrastructure projects as a key focus moving forward, as tunnelling sits as its core expertise. Acciona has built 600 kilometres of tunnels around the world, including 220 kilometres since 2005. Of all those kilometres of tunnels, Acciona has used advanced tunnel boring machines to dig 160 kilometres, and it currently owns 10 tunnel boring machines. Acciona has recently been awarded a contract to build a 20-kilometre tunnel in Norway.

“We saw this [Brisbane tunnel] as a clear opportunity to bring forward our core competency in tunnelling as our entry into the Australian infrastructure market,” says Mr. Fajardo. “Coupled with the council’s appetite for a competitive bid process and inviting international expertise, all the elements were well lined up for us to take on this work.

Mr. Fajardo explains that the key to bringing costs down, while completing a major project to the highest standards, comes down to an optimised design and construction plan.

“It all starts with a cost effective design,” Mr. Fajardo explains. Transcity carefully planned the highway connection points to the tunnel, so that the construction process would only minimally affect traffic flow. This reduced the need for traffic management during the project.

On the equipment side, the project used a conveyor belt throughout the construction, to both carry away excavated materials to the quarry, and also bring in bulk materials. Not only did this increase the efficiency of the operation, but it prevented the tunnel from being filled with transport trucks, and it cleared up traffic by keeping trucks off the road. This is one of the first times a reverse conveyor has been used at this level of tunnel construction, and Mr. Fajardo says that its success means it’s here to stay.

“That technology will remain here, and I suspect we will see it being used in the construction of tunnels moving forward,” he says.

Another key element to the project was the installation of a precast roof for the ventilation system within the tunnel. While these are often constructed ‘in-situ’, Mr. Fajardo says that by using precast materials, the team saved an impressive amount of time in constructing the tunnel, increasing productivity by half a kilometre a week.

With all these elements, the consortium excavated westbound 4.6 kilometres of tunnel in just six and a half months – a world record in tunnel construction.

The average construction time was 700 metres a month, with the project peaking at 900 metres a month.

“It’s clearly this efficiency that made the project cheaper,” explains Mr. Fajardo. “When you build a tunnel in less time it’s a huge saving.”

Mr. Fajardo further credits the shortened construction time and impressive costs savings to the combined efforts of its partner BMD Constructions, Queensland’s largest construction company and Italian Specialists, Ghella.

“It was a true mix of international expertise with local knowledge. Together, we ensured that every dollar counted, and that we were as efficient as we could be,” says Mr. Fajardo.

This efficiency extended beyond cost-savings, also to the consortium’s approach towards the community. With the tunnel going underneath 454 houses in Brisbane, the consortium had to tailor their plans according to the needs of the community. They made a few changes to the cross-passes to accommodate local needs.

When it comes to community relations, Mr. Fajardo can say that the team has worked hard to minimise impacts on the community. Furthermore, he says the council seemed quite happy with the results to date. With these advanced techniques and technologies set to stay in Australia, IPA’s Mr. Lyon says that Transcity has clearly set itself up as a worthy recipient of the award. He says the introduction of this technology show why heightened competition from international players working with local groups will be an important part of the future of Australia’s infrastructure work. “We really see the benefit of competitiveness here,” he says. “By heightening competition in project procurement, and inviting international players, it’s brought in new ways of doing things.”

Mr. Lyon further credits the insight of former Federal Minister Anthony Albanese, who found half a billion dollars in federal funding to support this project at the start of the global financial crisis. “It wouldn’t have happened without it,” he says.

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