Australia’s largest city is getting a new stand-alone rail network that will include 31 subway stations and more than 66 kilometers of new subway rail tracks. This will revolutionize the way passers-by get around Sydney. Doka is supplying engineering services and formwork materials for the mined tunnel concrete construction. The contract is the largest-ever project in the history of formwork engineers and scaffolding hire in tunnel construction.

When the Sydney Metro is extended into the Central Business District (CBD) and beyond in 2024, the subway network in northwest Sydney will run under Sydney Harbour to the new subway stations in the CBD and on to the southwest. Sydney’s new subway network will have a capacity of about 40,000 customers per hour, similar to other metro systems around the world, such as in Panama or Ankara. Sydney’s current metro system can reliably carry 24,000 people per hour.

A tunnel system for a wide variety of cross-sections
Doka is supplying engineering services and formwork equipment for work under the harbour and beneath the central business district. The Sydney Metro has become a showcase for Doka’s SL-1 load-bearing tower. The modular system provides complete formwork solutions for widely varying tunnel cross-sections, regardless of their shape or load. The SL-1 heavy-duty load-bearing tower is extremely flexible to adapt. The beams, ledgers and struts of the SL-1 can be arranged variably, ensuring optimum material utilization and enabling short erection times thanks to the pre-assembled formwork and beam components. Built-in safety systems ensure maximum workplace safety thanks to integrated working platforms and access ladders.

The Doka Global Expertise Centre Infrastructure (GEC INF), based at the headquarters in Austria, was also closely involved in the project. More than 20,000 engineering hours are required to design the formwork substructures for the concrete body that will support and line the massive underground caverns and tunnel crossings.

Special formwork solutions designed together with customers
Standardized but specialized Doka SL-1 components and modules were used for most of the requirements, but Doka Australia also tapped into the knowledge of its parent company to design and manufacture custom components for applications unique to the Sydney Metro project. The biggest challenge Doka’s engineering department faced was the application of formwork solutions for tunnel crossings of the new Martin Place, Pitt Street and Victoria Cross stations. Each individual tunnel cross-section requires a specific design for assembly outside the tunnel and placement into the cast-in-place concrete. Martin Place Station, for example, has nine individual tunnel cross-sections for which Doka designed custom formwork solutions.

The Doka team is in continuous contact with JHCPBG’s engineering teams and subcontractors, meeting regularly for joint meetings and workshops. “Doka has shown that they are ready to tackle the complex and unique challenges of our project, resulting in a highly satisfactory collaboration between the construction teams and Doka’s local and international offices,” emphasizes Benjamin Russo, Planning & Engineering Manager, Mined Tunnels.

This approach ensures that all parameters and requirements are taken into account in the search for the best solution for greater efficiency and safety during the works.