Bridges

This paper reports an independent study on the effects of Melbourne trams and Sydney light rail, and the heavy vehicle configurations defined in the draft AS5100.7 code on short to medium span bridges.

Existing bridges are often required to accommodate new light rails and/or new vehicles. A full assessment of these bridges for the new loads requires detailed investigation including inspection and load rating. In some instances where time and budget do not allow a detailed assessment, a preliminary assessment can be carried out by load comparison.

In this paper the results from a study where the effects of a variety of light rail, heavy vehicles, train design loads and traffic design loads are compared. The comparison of these loads is carried out for a number of span configurations and lengths. The results would help the rail and road authorities as well as bridge assessors to have an understanding of the different loads and their effects on their bridges.

A real example is also provided at the end of the paper where a bridge with two different span lengths was load rated. This example illustrates the use of the results of the comparison study.