Risk Based Management of the Swiss Railway Bridges

The Swiss Railway has an inventory of several thousand bridges. Up to now, condition classes of the individual bridges have mainly been used for the maintenance planning and planning of future costs. As part of a redesign of the maintenance management process, a change from the condition class-based approach to a risk-based approach is planned. In doing so, many additional parameters must be considered, such as estimates of the failure probability of all bridges, estimates of the traffic volume on the tracks and on the bridges etc. Based on existing models, for example from Al-Wazeer, Saydam and Strauss et al., a risk-based model was developed and adapted to the requirements of the Swiss railway. In addition, the model was implemented in a software and was linked to the existing SBB databases. The risk-based model contains for example results of the statistical analysis of bridge collapse data in order to quickly estimate the collapse frequency for many bridges, since complete probabilistic calculations are usually only available for a limited number of bridges. In addition, extensive investigations were carried out to estimate the number of possible victims.