Melbourne Metro Tunnel
Soil testing and geotechnical services for Australia's largest underground rail project, featuring twin 9km tunnels and five underground stations beneath Melbourne's CBD.
Project Overview
The Melbourne Metro Tunnel is Australia's largest underground rail project - an $11 billion investment connecting twin 9km tunnels beneath Melbourne's CBD. Our soil testing and geotechnical services supported critical phases of this complex infrastructure build, from initial ground investigation through construction monitoring.
Working with challenging conditions including the Melbourne Formation mudstone, Coode Island Silt, and complex groundwater systems, we provided essential soil testing data to help protect Melbourne's heritage buildings during deep excavations up to 40m. Our NATA-accredited laboratory testing ensured reliable results for foundation design and construction planning.
Geotechnical Challenges
Melbourne Formation Assessment
The tunnel passed through Melbourne Formation mudstone - a complex Silurian-age rock with varying strength and weathering patterns. Our soil testing helped characterise these conditions for tunnel boring machine operations and station excavations.
Coode Island Silt Behaviour
This soft, high-plasticity clay presented significant challenges for deep excavations. Our laboratory testing provided crucial data on consolidation properties and strength characteristics to support foundation design and settlement predictions.
Heritage Building Protection
Settlement tolerances of 5mm or less were required near heritage structures like Melbourne Town Hall and St. Paul's Cathedral. Our monitoring and testing supported ground movement predictions to keep these buildings safe.
CBD Construction Access
Limited site access in Melbourne's busy CBD required careful planning of our drilling and testing operations. We worked around existing utilities and transport networks while maintaining testing quality and safety standards.
Our Geotechnical Services
Site Investigation Program
We completed 180+ geotechnical investigations including standard penetration tests (SPT), cone penetration tests (CPT), and comprehensive NATA-accredited laboratory testing. This provided essential data on Melbourne Formation rock strength and Coode Island Silt properties.
Specialised Soil Testing
Our laboratory conducted detailed testing for consolidation behaviour, shear strength, and permeability characteristics of the challenging soft clays. All testing followed Australian Standards (AS1289) with full quality assurance procedures.
Ground Treatment Support
We provided soil testing support for jet grouting operations at cross-passage locations. Our testing helped verify ground improvement effectiveness and ensure design parameters were achieved for safe tunnel construction.
Environmental Assessment
Completed contamination assessments across multiple CBD construction sites. Our testing identified soil classification requirements and supported waste management planning throughout the construction phases.
Testing Methodology
Soil Investigation
SPT, CPT, and comprehensive laboratory testing across Melbourne Formation
Geological Formations
Melbourne Formation mudstone, Coode Island Silt, Quaternary sediments
Groundwater Management
Multi-aquifer assessment with complex CBD hydrogeology
Settlement Monitoring
Real-time monitoring for heritage building protection
Ground Treatment Support
Testing for jet grouting and ground improvement works
Environmental Testing
Contamination assessment and soil classification
Project Outcomes
Project Timeline
Site Investigation
2017-2018SPT, CPT and laboratory testing across tunnel alignment
Ground Characterisation
2018-2019Melbourne Formation assessment and soil classification
Construction Monitoring
2019-2022Real-time monitoring and ground treatment support
Environmental Testing
2020-2023Contamination assessment and soil management
Project Completion
2023Final reporting and handover documentation
Project Details
Services Provided
Project Progress
Need Soil Testing Services?
Contact our team for geotechnical investigation and NATA-accredited laboratory testing.