Bridges

Major Road Projects Victoria upgraded the M80 Ring Road between Sydney Road and Edgars Road by building new lanes in each direction, lengthening existing freeway ramps, and installing ramp metering technology, with braided ramps between the Hume freeway and Edgars Road. CPB Contractors was awarded the contract to build the upgrade and engaged AECOM to undertake detailed design on this section of the project.

The Blaxland Avenue overpass is a cable stayed bridge and is a key feature of the M80 Ring Road in this area. It provides a north-south connection for pedestrians and cyclists across the M80 Ring Road. Prior to the upgrade, the main span crossed over all traffic lanes. However, the upgraded freeway ramps will be longer and located outside the main span. As a result, the approach ramps of this bridge needed to be relocated further away from the M80 main line to accommodate the upgraded freeway ramps, and a longer bridge was required to connect the relocated approach ramps.

The Reference Design proposed that the entire Blaxland Avenue overpass be demolished and replaced with a new, longer bridge. AECOM developed a design solution that retained the main span and towers of the existing cable-stayed bridge. The bridge was modified by lengthening the back spans and replacing the back cable-stays to clear the upgraded ramps. Several design challenges were overcome to achieve this design solution. This paper describes the scope of the Blaxland Avenue overpass modification and presents the innovative design solutions which minimised the impact on M80 traffic and the local community.