Bridges

Over recent years, Public Transport Victoria through its operator Yarra Trams, has been gradually introducing new class trams (of which the E Class is the heaviest and longest) on Melbourne’s tram network.

This has necessitated a review of the capacity of the bridges located on the network, of which there are approximately 50 in number, and most of which are VicRoads assets.

Due to the relatively short time frame in which the new trams are being deployed, VicRoads has adopted an hierarchical assessment methodology which can range from ‘simple comparative assessments’, (where the load effects of the new trams on a bridge are compared to the load effects from the original design loads) to ‘complex analytical investigations and load rating’.

Issues that posed significant challenges include insufficient guidance in AS5100 on how to treat the co-existence of tram and road vehicles on bridges, and the associated risk of different and inconsistent assessment assumptions and loading parameters, and the lack of as-built information for some of the older bridges.

This paper reports on the types of trams on the network, the bridges that have being assessed, the various assessment methods employed and the results of these assessments.