Engineering excellence beneath Melbourne’s Eastern Freeway

Country

Australia

City

Melbourne

Timeline

2025

Application

Sewer

Total Length

1350 m

+

By combining local manufacturing, advanced GRP technology, and precision trenchless installation, Amiblu helped future-proof one of Melbourne’s most complex infrastructure projects – the Eastern Freeway and North East Link integration.

The Eastern Freeway Widening in Melbourne is one of Australia’s largest and most important transport infrastructure projects. To ease growing traffic congestion and improve capacity, the Victorian State Government launched the project to expand and modernise the freeway and connect it with the new North East Link.

However, a significant engineering challenge soon appeared: several large trunk sewer mains owned by Yarra Valley Water and Melbourne Water ran directly beneath the freeway and the planned interchanges. These vital assets, some decades old, couldn’t be simply removed or replaced using open-cut methods due to their size and the dense urban surroundings. Keeping the sewer system running while widening a live freeway became a major technical task.

Amiblu was chosen as the preferred supplier for this complex work because of its early involvement and strong technical support during the planning stage. By working closely with the design and engineering teams, Amiblu helped develop an optimised sewer realignment suited to the site’s operational and environmental needs. Another key advantage was Amiblu’s ability to provide Australian-made GRP pipes, which ensured reliable supply, shorter delivery times, and local industry support – all crucial for a project of this size and importance.

The installation used Amiblu Flowtite GRP jacking pipes and GRP manholes, combining trenchless construction with precise engineering. The new DN 1500 GRP pipeline, stretching 1.35 kilometers, was built right next to an existing Amiblu HOBAS GRP sewer that has been in service for 30 years. To keep that line operating, the new pipeline had to be aligned and jointed with great accuracy to create a smooth connection between the two systems. The trenchless microtunnelling method reduced surface disturbance – essential in such a busy area – and provided long-lasting strength and corrosion resistance under challenging soil and groundwater conditions.

One of the most notable features of the project was the use of lightweight GRP manholes instead of traditional concrete ones. This made installation faster and easier, often achievable in a single lift, which cut down handling, construction time, and costs. GRP manholes also offer excellent corrosion resistance and watertight performance, ensuring minimal maintenance throughout their lifespan. This reliability is especially important for infrastructure located beneath one of Melbourne’s busiest transport corridors.

After successful completion, Melbourne’s freeway corridor now includes a modern, durable underground network designed to serve the city’s needs for decades to come. Amiblu’s GRP technology and engineering expertise have helped deliver a critical wastewater solution that supports the long-term efficiency, sustainability, and safety goals of Victoria’s key transport upgrade.