Bridges

The Causeway Pedestrian and Cyclist Bridges Project in Australia delivers a landmark active transport connection across the Swan River in Perth, Western Australia.

Consisting of two cable stayed bridges, the constructed option limited the number of river piers to just three, acknowledging the spiritual and cultural importance of the Swan River (Derbal Yerrigan) to Perth’s first nations peoples.

Point Fraser Bridge comprises a single 52 m high pylon representing a boomerang. The bridge is asymmetric with a 48 m side span and a 99.7 m main span supported by cables attached to the inner side of continuously curved bridge deck.

McCallum Park Bridge comprises two 46 m high pylons representing digging sticks. The bridge is symmetric with 60 m side spans and a 155 m center span supported by cables attached to the inner side of the S-shaped bridge deck.

The ambitious design requirement of a minimum 6.0 m wide deck with single sided cable attachment points required grade 400 MPa weathering steel for the deck and the pylons. A comprehensive wind-tunnel testing program was conducted for both bridges, including static and aeroelastic testing of cables to allow for a fully integrated stay cable lighting system. The comfort criteria for footfall excitation on the project was defined for high density pedestrian traffic and for a marathon event with hundreds of joggers on the bridges.

This paper discusses the general design development of the bridges taking architectural input, wind and footfall dynamics as well as construction sequencing into account.