Risk assessment of all Swiss railway and highway bridges

This paper presents the risk assessment of all bridges on the Swiss railways and Swiss highways, overall app. 14 000 bridges. In contrast to the usual approach, this study uses adjusted collapse frequencies instead of failure probabilities. The adjustments are based on statistical and AI evaluations of collapse databases and literature reviews and are carried out by factors specific to each bridge based on bridge databases. In addition, the consequence parameters for the bridges are determined specifically on the means of transport, the traffic volume, the detour route, and potential loss of life. As a result, the bridges are divided into risk categories and risk lists. Besides a short explanation of the procedure, several related topics are briefly discussed. For example, the consequences of the analysis in terms of bridge closure and further steps are also indicated. The paper is an extension of a former investigation of the Swiss railway bridges only. The paper finishes with a short discussion of open issues such as correlation either between certain adjustment factors and between certain bridges, for example during a flood.