West Gate Bridge - Strengthening of the Concrete Viaducts

The 2.5km long West Gate Bridge comprises an eastern and western concrete approach viaduct, 871m and 670m respectively long either side of the 848 m long cable stayed steel box girder main span section. The key objective with the West Gate Bridge Strengthening Project was to increase the number of lanes in each carriageway from 4 to 5 to reduce traffic congestion on the M1 Freeway.

This paper describes the elements used to strengthen the concrete viaducts including carbon fibre reinforcement and additional post-tensioning. An extensive system of temporary platforms was required for access to the outside of the box girder. Given the weight of these platforms and the limited capacity of the unstrengthened bridge, particular care was required with the staging of the works, traffic controls and platform movements.