Metro Tunnel Geotechnical Monitoring Melbourne

About Metro Tunnel

The Metro Tunnel is Melbourne’s largest rail project since the City Loop was built in the 1970s. It involves building twin rail tunnels and five underground stations from North Melbourne through to the Domain precinct, south of the CBD. New underground walkways will connect Town Hall Station through to Flinders Street Station and State Library Station to Melbourne Central Station, allowing seamless connections for commuters between City Loop and Metro Tunnel services.
To enable a fast start when the Main Works contractor was selected, a significant Early Works package was awarded to John Holland. It included the sinking of 3 major shafts on the critical path in a complex CBD environment, as parts of the future CBD North and South stations.

The Challenges

Aside from the traditional – although real – challenges of deep excavations in dense urban environments, the scope of installation was large over a very short period, and the neighbouring community were very sensitive – with research grade scientific laboratories immediately adjacent to piling and excavation works.

What we’ve delivered

A comprehensive and integrated real-time monitoring system with QA/QC, trigger alarm and reporting services. The scope of sensors included geotechnical, survey/deformation & environmental instrumentation. To deliver a quick response for the demanding stakeholders, a wireless data communication network has been deployed over the city to collect and report data in real-time. Our web-based sensor data managment platform, Geoscope, was used to process the data, trigger alarms when necessary and produce daily, weekly and monthly reports.
We’ve also deployed our patented technology “”Evolution”” within the shafts, which allows for sub-millimetric monitoring with Total Stations without local stable references.