The West Gate Tunnel Project is set to deliver an efficient alternative to the West Gate Bridge. The completion of this project will provide a quicker and safer journey for commuters.

Prior to tunnelling commencement, a 690m section of the North Yarra Main Sewer required diverting.

The Northern Portal is a tanked bottom up structure with the excavation supported using a temporary secant pipe wall and steel strutting support system. The excavation facilitated the launching of 2 X 15.6m Tunnel Boring Machines for excavating the West Gate Tunnels.

Our Role

Geotech were engaged to supply, construct and deliver the ground engineering works to be incorporated into the Northern tunnel portal area for the West Gate Tunnel Project.
Detailed scope of works included;

• North Yarra Main Sewer Upstream and Downstream connection and retrieval of approx. 5500m X 900mm diameter Secant Piles (hard and soft).
• The construction of a Temporary (Concrete) Guide Wall. This included steel hollow sections and stabilised sand
• NYMS TBM Retrieval Ground Improvement

Disciplines covered:

• Secant Piles
• CFA Ground Improvement Works