Probability-based assessment of highway bridges according to the new Danish guideline

This paper describes the newly developed Danish guideline for probability-based assessment of highway bridges. The guideline, the first of its kind in the world, describes how probability-based assessment of bridges can be performed in accordance with the requirements for the safety level prescribed by the Danish Roads Directorate (DRD). The guideline specifies principles for modelling uncertainties including treatment of model uncertainties. The requirement in the ultimate limit state for the structural safety is specified with reference to failure types and failure consequences. The guideline, in conjunction with codes of practice, provides the DRD with the legal justification necessary for application of probability-based approaches in Denmark. While the purpose of the guideline is to serve as a basis for the probability-based assessment of Danish bridges, it can also easily be applied in other countries. This paper presents, through a practical example, the application of the guideline to actual bridge structures.