Bridges

The New Nowra Bridge is the third crossing over the Shoalhaven River at this location, and will carry all northbound traffic on the Princes Highway through Nowra. It is one component of the design and construct Nowra Bridge project, which widens 1.7 kilometres of the Princes Highway including the bridge approaches, key intersection improvements and modifications to the local road network.

The horizontal road alignment is straight over the bridge structure, while the vertical alignment is on a crest curve with a high point positioned on the bridge structure itself, making it suitable for incremental launch construction. The bridge is located to the west (upstream) of the two existing bridges crossings of the Shoalhaven River and it has an overall length of 359.7m. The 10-span length and arrangement were dictated by the geometry of the existing bridge.

The piers comprise of reinforced concrete V-shaped elements supported on pile caps and piles. With the exception of the northern abutment, which has a spread footing, and pier 1 with concrete bored piles, the remaining bridge foundations utilise driven steel tubular piles with concrete infill plugs due to the depth of up to 58 metres to bedrock below the tidal waters.

The double T girder concrete superstructure is continuous for the full length and it has longitudinal and transverse post-tensioning. The casting yard on the southern foreshore was established using a 4-bay process behind the abutment to allow for reinforcement placement, segment construction and curing and fit-out from the safety of land. Design innovation of the southern abutment enabled support for launching jacks and integration of temporary casting area structures to provide lateral stiffness during launching.

The paper discusses key design and construction features of the bridge, including its proximity to the existing bridges, geometry constraints, articulation, safety efficiencies, environmental constraints, construction sequences and methodologies. It will also present the main innovations generated by the project team and the construction challenges during the delivery of the project.