Last section of SA North-South Corridor progress towards construction

Early works on the final piece of South Australia's non-stop North-South Corridor is progressing well with Phase One of investigations about to conclude and procurement for Phase Two commencing this month. 

The Torrens to Darlington (T2D) section of the North-South Corridor is the last section to be delivered to complete the route. 

This section of the corridor is anticipated to be the most complex to deliver due to several factors such as location, ground conditions, unique heritage assets and social character. 

The first phase of investigations commenced in August 2020 and is expected to be completed by the end of this month. Phase One involved examining about 200 locations along the route. 

On the other hand, Phase Two investigations will focus on up to 200 locations along the southern section of the project, between Anzac Highway and Darlington. The data from this investigation is going to be used to inform the reference design for the project. 

“The final stage of this project is hugely complex and it is important we undertake these investigations to inform the planning process. 

“It is important to note the locations chosen have been selected to build a comprehensive corridor-wide ground model and do not necessarily correspond to areas that will be impacted by the project in the final design,” Minister for Infrastructure and Transport Corey Wingard said. 

Scope of works under Phase 2 investigations include: 

• Geotechnical investigations including borehole drilling, standard penetration testing (SPT), laboratory testing and cone penetration testing (CPT) 
• Ground water investigations, monitoring well installation, soil and groundwater sampling and testing 
• Hydrogeological investigation including installation of monitoring bores and production bores 

Works are expected to commence in April 2021 and completed by the end of the year. 

For more information on the procurement for Phase Two, you can visit Tenders SA. 

The $5.4 billion T2D project will deliver a 10.5-kilometre highway with a hybrid+ design. This design option features a mix of tunnels, lowered and ground-level motorways along with overpasses / underpasses at key intersections. 

This last section of the North-South Corridor is going to be built in two stages, namely: 

• Southern Tunnel (Stage 1) – linking Anzac Highway to Darlington 
• Airport Link and Northern Tunnel (Stage 2) – linking River Torrens to Anzac Highway 

The multi-billion-dollar T2D project – which is jointly funded by the Australian and South Australian Governments – is anticipated to create up to 4,000 jobs during its construction. 

Once open to traffic, motorists travelling along the North-South Corridor between River Torrens and Darlington will be able to bypass 21 sets of traffic lights, reducing travel times by about 24 minutes. 

T2D is due to be completed in 2030. 

Source: Premier of South Australia – Media Releases; SA Department of Infrastructure and Transport (1, 2)