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Tunnel investigations progress to second phase

18 February 2021

Hon Corey Wingard MP

Minister for Infrastructure and Transport

Thursday 18 February 2021


Tunnel investigations progress to second phase

The Marshall Liberal Government will continue early works for the final 10.5 kilometre stretch of the North-South Corridor with procurement to commence on the second and final phase of technical investigations.

The hybrid+ option will transform the 10.5 kilometre stretch between River Torrens to Darlington over the next decade, creating up to 4,000 jobs.

Due to its location, ground conditions, unique heritage assets and social character, the final section of the corridor is the most complex piece of the puzzle to deliver and will include a combination of tunnels and surface-level motorway.

Phase One investigation works began in August 2020 and are due for completion by the end of February 2021. Phase One examined approximately 200 locations along the 10.5 kilometre corridor.

Procurement for Phase Two ground investigations will also begin this month and will focus on approximately 200 locations on the southern section of the project alignment between Anzac Highway and Darlington.

Minister for Infrastructure and Transport, Corey Wingard, said the investigations form an important part of the project.

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

“When Phase One is complete, experts would have drilled approximately 5.5 kilometres – roughly the distance from the CBD to the airport.

“Some of this data has never previously been obtained in metropolitan Adelaide and will benefit the state for years to come.

“This second phase will focus on the southern section of the alignment and will help to inform the reference design.

“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.”

The scope of works for Phase Two 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

Phase Two ground investigations are expected to begin in April and will be completed by the end of 2021, weather permitting.

More information about the procurement can be found at Tenders SA.

The Australian and South Australian governments have committed $5.4 billion towards delivering the T2D Project.