- Publication no: ABC-MAR021-11
- Published: 31 October 2011
The existing rail track support on the Sydney Harbour Bridge consists of timber transoms and deck supported on steel stringers and cross-girders of the Bridge. The deck area of the Bridge is solid except in the rail corridor. Not having a solid deck in the rail corridor has posed many problems including durability of the steel structure. RailCorp has considered the replacement of the highmaintenance timber transoms and decking with a durable solid deck.
The project has been awarded to Opus International Consultants, who has partnered with Heggies (Noise and Vibration) and Hughes Trueman (Heritage Impacts). Options have been investigated considering key construction issues such as the rail possession periods and traffic lane closures available on the Bridge, and the retaining of the existing rail levels.
Concrete, steel, and composite materials have been considered in the optioneering stage as the replacement deck. However, precast concrete deck has scored ahead of other materials due to its known longevity and the ease of replacement during the limited rail possession periods.
In the Preliminary Design two main options have been developed: a composite deck to the longitudinal steel stringers and non-composite deck as a replacement for the existing timber transoms and deck. Both have their own merits. The composite deck has better strength capacity and enhanced fatigue performance than the noncomposite deck.
This paper presents the detailed concepts development and preliminary designs of the above options.