Bridges

Sydney Gateway is an NSW Government initiative to improve road and freight rail transport to and from Sydney Airportís Domestic and International Terminals and Port Botany. Sydney Gateway completes the missing links in the motorway network and will increase capacity and improve connections to the ports to assist with the growth in passenger, freight, and commuter traffic movements across the region.

Twin network arch bridges on Airport drive spanning the Alexandra canal are signature structures that lead to the International Terminal. Both bridges are 100m long, carry four lanes of traffic, and are constructed by launching them across the canal. The bridge location is highly constrained with adjacent roads, pedestrian paths, air transport, waterway, and numerous utility infrastructure. The geometry of the bridge and the selected construction methodology offer a cost-effective solution to address the site constraints while satisfying clearances and various stakeholder requirements. The optimized material quantities of the network arch solution resulted in a lightweight and elegant structure spanning the constraints. The low structural depth of the network arch simplifies the tie-in with existing roads, facilitates easier traffic staging, and provides sufficient flood freeboard. This paper will focus on the design development of the network arch bridge to satisfy the various constraints at the brownfield bridge site, design challenges for the long-span structure including wind tunnel testing to ascertain the stability of the bridge against aeroelastic instabilities, construction methodology including the launching of the arch bridges over the Alexandra canal and aesthetic aspects of the bridge such as the bespoke feature lighting.