Experience with Probabilistic-based Assessment of Bridges

This paper describes the practical experience from probabilistic-based assessment of bridges in Denmark and Sweden. The methodology is based on an individual approach for bridge safety assessment based on the concept that a bridge does not necessarily have to fulfill the specific requirements of a general code, as long as the overall level of safety defined by the code is satisfied. The purpose of the individual approach is to cut or reduce the strengthening or rehabilitation cost without compromising on the level of safety. The safety evaluations are based on probabilistic methods in which the uncertainties of the specific bridge condition and the local traffic situation can be taken into account consistently. It could be said that this approach establishes a "code" with specific partial safety factors for the individual bridge. Four practical examples are presented. It is recommended that the approach be considered as a possibility in any strengthening and repair projects with the purpose of obtaining large cost savings.