Building the Metro Tunnel presents many opportunities to innovate, especially given the complexities surrounding the range of geological conditions and inner-city urban environments.
“It is going to be challenging for everyone, since we are working in a live environment right in the heart of an active city with multiple stakeholders – some of whom have unique requirements,” says Rob Alexander, Major Project Executive for WSP’s Transport business. “For example, we are tunnelling and creating a new station right in the heart of a research and medical precinct which houses important equipment.
“Our transport experts have a demanding job ahead of them that includes minimising disruption to residents, businesses and public events as well as road traffic, pedestrians, cyclists and existing public transport and freight services. They will also need to navigate the existing underground infrastructure including the City Loop, CityLink tunnels and services such as water, gas and electricity. Additional considerations include excavating through a range of varying geological conditions including rock, sands, clays and silt as well as managing the removal and disposal of all this material. And, tunnelling will take place under two significant waterways, the Yarra River and Moonee Ponds Creek.”
A unique feature of building the Metro Tunnel Project is the innovative way the two new underground stations in the CBD will be constructed. Instead of the traditional design of two tunnels separated within the stations by a cross passage, the trains will pass through the two newly constructed underground city stations via one huge ‘trinocular’ tunnel.
“The result is the creation of a wide-open space at the CBD stations allowing for the concourse and platforms to be integrated on a single level,” says Mr Alexander. “Ultimately, this will be one of the widest underground metro platforms in the world.”
Maximising Safety and Security
Providing a safe and secure passage for millions of rail users is vital. A lot of thought has already been given to the structural safety and ventilation of the metro system, and in particular smoke ventilation.
“Our fire team is working on the underground interchanges between the new Metro Tunnel and the existing City Loop,” explains Mr Bretherton.
WSP will also assess the risk and potential vulnerability of the tunnel structures to determine the preventative, protective and remedial measures to improve safety and security.
Enabling a Sustainable Future
Through the delivery of this new infrastructure, the Project is committed to connecting communities in the healthiest, most sustainable way possible. The Project wants to ensure a lasting legacy for present and future generations for a more liveable Victoria – environmentally, socially and economically. To help achieve this vision, the joint venture engaged the services of our Sustainability team.
Bernadette Fitzgerald, WSP’s Associate Director for Sustainability, says, “The implementation of the Project’s sustainability vision has been imprinted into the design DNA since the tender stage. We have been working with the design and construction joint ventures – providing advice to enhance the sustainability outcomes throughout the delivery and operational phases of this significant asset. This has included analysis of services to identify design options to reduce and efficiently manage resource consumption - including energy, water and material saving initiatives, as well as ways to avoid, minimise and offset harm to the environment and the loss of biodiversity. Protecting and conserving the natural environment is also key and we are advising on how to build resilience into the asset to prepare for the challenges presented by climate change.
“We are proud of the work we have been undertaking – particularly working to develop a sustainable procurement approach and to embed biophilic design outcomes into the station designs.