Bridges

Outputs from bridge assessment to AS 5100.7 are deterministic, expressing safety as a subjective and conservative binary (yes/no) measure. With Australia and New Zealand seeing increases of road freight demand under finite bridge infrastructure funding, bridge owners look towards higher tiers of assessment to better utilize existing ageing bridges. Although AS 5100.7 allows the occurrence of these activities, there is no guidance for such methods. Internationally, the next tier in assessment is the use of probabilistic approaches such as structural reliability methods, providing objective and quantifiable measures of safety on a continuum. This paper summarises the findings, learnings, and progression since the development of a probability-based bridge assessment (PBBA) framework for the Australasian context, seen in Austroads Report AP-R617-20. The results show the PBBA framework can indicate significant reserve in safety compared to deterministic measures, allowing potential operational and financial benefits. Given these benefits, there exists the need to promote the adoption of PBBA as higher tier bridge safety assessments in Australasian practice. By providing objective and accurate safety assessments, the PBBA works towards more fit-for-purpose assessments, better utilising bridge assets, thereby facilitating an optimally sustainable and productive road transport network.