Demolishing an existing bridge over a railway line and replacing it with a wider, higher bridge over two weekend closures in bustling Sydney. Mission impossible? Not at all, thanks to innovative construction techniques and a well- planned programme.
The original Amy Street rail overbridge was built in 1921. A two-span bridge over the railway line, it carried two lanes of traffic with narrow footpaths either side. Fast forward to 2013 - traffic had increased and this caused congestion.
Auburn Council knew the bridge needed to be upgraded from two lanes to four to improve traffic flow and increase capacity. More rail traffic also meant the bridge needed to accommodate two future rail tracks, plus higher vertical clearance to allow for overhead wiring maintenance.
As well as designing and delivering a future-proofed solution to ensure smoother, quicker journeys, we needed to tackle tight site constraints. These were varied and included a rail station platform only 15m north of the bridge, nearby building developments and plenty of rail infrastructure (like signals and gantries). Additionally, to avoid too much traffic and rail disruption, construction was only allowed over a 16-week period with just two weekend closures.
Yet despite all these challenges, the bridge was completed and opened as planned at the end of September 2016. We made this happen by including innovative construction methodology in our design, close coordination with all stakeholders, and through careful planning that maximised the construction period.
Read the paper presented on the innovations surrounding the Amy Street Rail Bridge at the 2017 Austroads Conference here.