BG&E was engaged by Fulton Hogan as a structural design partner for the Design and Construction (D&C) of the Molonglo River Bridge (subsequently named the Malcolm Fraser Bridge), which formed part of the Majura Parkway project in ACT.

Majura Road, once the main artery through the valley, was a single-carriageway rural road that handled around 18,000 vehicles daily but could not accommodate future traffic increases. The new Majura Parkway has replaced this link, improving connectivity in the region.

Following the successful tender submission, BG&E completed the design and documentation of a pair of four span, 202 metre long incrementally launched concrete box girder bridges across the Molonglo River and Morshead Drive.

BG&E’s approach responded to the key design challenges

• Road alignment – the bridges were designed to accommodate differences in alignment between the two carriageways within the bridge deck while maintaining the same launch geometry for both. This enabled the two bridges to be launched from the same cast bed and formwork.
• Skewed supports – the bridge design required launching over skewed supports, including a skewed launch nose and end diaphragms. BG&E developed a scheme to remove the second-stage pier diaphragm beams, greatly simplifying the reinforcement layout at these locations.
• 3D modelling – the two bridges were fully modelled using 3D CAD to facilitate the setout of all elements including precast barriers, railings, expansion joints, drainage, deck end clearances and structure geometry. This model was also used by our CAD team to assist with the reinforcement detailing of complex diaphragm zones to reduce the risk of clashes and delays during the construction phase.