Practical implementation of probability based assessment methods for bridges

This paper presents the practical implementation of probability based assessment methods to road and rail bridge structures. For the structures analysed, modelling of the critical limit states is described as are the statistical techniques employed in modelling the loads and resistances. The overall aim of the analysis was to achieve higher load ratings for the structures considered than those which resulted from traditional deterministic analysis. Ultimately the benefits to bridge owners/managers of performing probabilistic assessments are apparent from the results, which consistently provided (a) higher load ratings for the bridges considered and (b) considerable financial savings (both direct and indirect) through the avoidance of unnecessary repair/replacement of serviceable highway structures. Examples presented in the paper demonstrate direct monetary savings in excess of $US30 million.