Connecting SA’s north and south

NATIONAL PRECAST MEMBER HUMES IS SUPPLYING PRECAST CONCRETE ELEMENTS INTERGRAL TO THE DARLINGTON UPGRADE PROJECT.The Darlington Upgrade Project is another important stage in the delivery of Adelaide’s North-South Corridor and will provide an upgrade of approximately 3.3 kilometres of the existing Main South Road, including:

• A non-stop motorway between the Southern Expressway and Tonsley Boulevard

• A lowered, non-stop motorway passing underneath Flinders Drive, Sturt Road, Sutton Road/Mimosa Terrace and Tonsley Boulevard

• Grade separation of the Main South Road/Ayliffes Road/Shepherds Hill Road intersection

• Main South Road (at grade) surface roads along both sides of the lowered motorway to provide connections to Flinders Drive, Sturt Road and most local roads

• Full free flow interchange at the Southern Expressway/Main South Road with dedicated ramps providing direct access to the new motorway and Main South Road

The $620 million project is being delivered by Gateway South – a joint venture between Fulton Hogan and Laing O’Rourke – and features precast concrete manufactured by National Precast member, Humes.


Precast manufacturing is an integral component of the project, with a number of precast concrete arches manufactured by Humes, being installed for the Main South Road bridge over the Sturt River at Bedford Park.

Nine two-piece precast concrete arches – 18 segments in total – were manufactured by the precaster.

The structure is a critical part of the approach to two 180-metre bridges over the Southern Expressway, providing access to the lowered motorway and to the surface road for traffic.


As the arches were installed in a critically sensitive environment adjacent the Sturt River, efficient installation was at the heart of the reason for using precast concrete.

Traditionally known as the Warriparri, the Sturt River is of high importance to the Kaurna people and both the river and surrounding Warriparinga area are of significance in Kaurna culture.

Recognising this, Gateway South’s Senior Project Engineer, Colm O’Sheehan from Fulton Hogan, says they endeavoured to minimise the amount of in-situ work and the solution hinged on precast.

“Precast was the only option because the river is of importance to the local Indigenous people and so the less work we could do on site, the better,” Mr. O’Sheehan explains.

“The whole area surrounding the river is also of significance, so precast made things a lot easier from a community perspective,” he adds.


The project is also engaging with the local construction industry to deliver sustainability benefits to not only the environment, but to the economy and the community as well.

Bringing economic benefits to South Australia’s contractors and suppliers, the project is driving workforce participation and increasing the employment of apprentices, trainees and displaced automotive employees.

The project will support approximately 370 jobs per year during construction.

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