Bridges

The M80 Ring Road Upgrade is a $2.25 billion project, jointly funded by the Federal and State Governments. The section between Furlong Road and Sunshine Avenue was awarded to BMD Constructions, with GHD as the lead design consultant. BMD’s Design and Construct contract was to construct two extra lanes in each direction including widening of the existing bridges over Furlong Road. The new bridges were required to maintain the same appearance of the existing structures that were constructed in situ with no traffic and using formwork. Given the roadway underneath the bridges is now a busy corridor, replicating this original construction method to achieve the same appearance was not an option. GHD developed an innovative solution involving the use of a series of precast inverted T-beams stitched together transversely at the bottom flange, an in situ concrete deck on top and made continuous longitudinally using cast in situ diaphragms and post-tensioning. This approach significantly reduced impacts on the existing roadway during construction by eliminating the need to construct temporary works over Furlong Road.This paper discusses the various engineering challenges presented by the project and methods used to overcome them. Completed in March 2012, two months ahead of the scheduled completion date, the project won the Victorian 2013 Civil Contractors Federation Earth Awards – one of the most prestigious awards in civil infrastructure.