Bridges

The new Dudley Street Bridge is a 74m long structure supporting the Up and Down Regional Rail Link tracks to provide access to Platforms 1 to 8 at Southern Cross Station. The bridge is part of the $3.65 billion Regional Rail Link project in Victoria, section being delivered by the City to Maribyrnong River Alliance (Regional Rail Link Authority, V/Line, Metro Trains Melbourne, John Holland, Lend Lease, Coleman Rail, AECOM and GHD).

Although the Bridge was not part of the reference design, providing the bridge resulted in a major project wide benefit. The bridge removed extensive crossover works and associated rail occupations thereby achieving complete separation of the regional trains from the metropolitan network.

Major challenges encountered in developing the final design solution include locating the bridge foundation directly on top of the underlying Melbourne Underground Rail Loop tunnel, working under rail occupations and road closures, allowing for close proximity of existing buildings including Festival Hall, and major in-ground services including a high pressure gas main on top of the tunnel roof.

A number of innovative design solutions including precast piers and headstocks and prefabricated steel concrete composite deck units were adopted to overcome the above challenges and to minimise the impact on adjacent operational rail. Also, given the high profile location of the bridge, significant urban design elements were incorporated in the design.

This paper presents the design and construction challenges and state-of-the-art solutions adopted by the project team. Major bridgeworks were successfully completed in August 2013 with minor elements completed in early 2014.