Bridges

Melbourne’s West Gate Bridge, first opened to traffic in 1978, is around 2.5km long and comprises a five-span steel box girder portion over the Yarra River and two continuous concrete box girder approach viaducts.

This paper presents the findings from monitoring, over a period of 12 months, of the thermal movement of the steel bridge and the two concrete viaducts. It provides a:

• comment on the relevance of this information to management of West Gate Bridge
• description of the method and equipment used to measure and record the bridge movement
• summary of the findings
• proposed algorithm for the prediction of bridge thermal movement in response to a projection of ambient temperature
• comparison of the results with predictions derived by the application of AS5100.2.

The paper comments on the factors that influence the temperature gain during the course of a day and how these influences are reflected in the results.