Abstract

Sydney Metro’s expansion into the north west of the city has recently included the construction of

4.5 km of elevated viaduct that includes a one of kind cable rail bridge. Set out on a 403 m horizontal

radius with a 130 m long main span, the bridge’s prestressed precast concrete segmental deck is

supported by a single plane of cables. An integral part of the design challenge was the need to

construct the bridge using the same overhead gantry used to construct the simply support spans on

the main viaduct. Using the gantry, the three span structure was first built as a continuous girder

supported on the four permanent supports with five temporary supports. The deck sections were

erected as a series of cantilevers, then connected into a continuous girder and finally, after the

release of the temporary supports, converted into a cable supported structure. A feature of the

design was the staging of the deck prestressing that avoided removing strand installed during a

previous stage as the bridge metamorphized from a seven-span structure to a three-span structure.

Keywords: precast segmental, erection engineering, cable stayed, temporary works, rail, curved