Bridges

The Molonglo River Bridge project is a critical piece of infrastructure that will provide a major arterial road link, significant utility services and a transport corridor to the future Molonglo Town Centre. The project, which includes a provision for future light rail, will improve access around the Molonglo Valley and keep the growing town centre and the wider city moving.

GHD and pitt&sherry, in association with the international consultant COWI, were engaged by BMD to undertake the tender and detailed design for the project. Construction started in January 2024 and the project is due to be completed in the third quarter of 2026.

The project includes the construction of a new 200-metre-long bridge over the Molonglo River, 1.7 km dual carriageway, separated paths, new intersections, lighting, stormwater management, landscape rehabilitation and four pedestrian underpass bridges.

pitt&sherry, in association with COWI, prepared the detailed design of the new three span haunched steel box girder bridge over the Molonglo River. The bridge, when completed, will have the longest weathering steel single span of 80 m, in the southern hemisphere.

The bridge superstructure is composed of weathering steel haunched box girders and the pier columns are encased in non-structural weathering steel to match the architectural properties of the existing Butters Bridge to comply with the 'Family of Bridges' concept being developed by the ACT Government.

A joint submission was made by the ACT Government and BMD to the Infrastructure Sustainability Council, which will be the first project in Australia to be considered with the requirements for delivering an As-Built Infrastructure Sustainability Council (ISC) rating under version 2.1.

This paper sets out the critical project planning decisions, technical design innovations, sustainability enhancements and constructability considerations from the perspective of the key client, designer and contractor.