The major phase of geotechnical investigations to inform tunnel and station designs for the Metro Tunnel Project is now complete.

Over the past two years more than 270 boreholes have been drilled up to 50 metres deep along the Metro Tunnel alignment.

Over 9800 metres of rock samples were collected along the project alignment, equivalent to 30 Eureka Towers stacked on top of each other.

The samples show that the sedimentary rock beneath Melbourne was formed 416 to 440 million years ago, and are providing critical information about the ground conditions we will encounter when we tunnel under the city.

For more information see our Geotechnical investigations webpage.13/17.