Bridges

The M80 Ring Road Upgrade is a road project by VicRoads to improve the 38 km freeway extending from Laverton North to Greensborough. The contractor is Fulton Hogan and KBR is the lead designer for the detailed design of a section between Edgars Road and Plenty Road.

This section includes six major existing bridge structures which required widening to accommodate additional traffic lanes and strengthening for the design live load of 75% of SM1600. This paper concentrates on the twin bridges over Dalton Road, High Street and Plenty Road.

Bridges over Dalton Road and High Street were supported by sill abutments on reinforced soil structure (RSS). The Plenty Road bridges consisted of two-span Super-T structures made structurally continuous over the internal support.

This paper focuses on the two main engineering challenges faced during design and construction:

• underpinning of existing sill abutments with piled foundations to suit the wider road
• strengthening of existing superstructure beams by carbon fibre reinforced polymer.