This paper presents results of bridge scour risk assessment by using two qualitative methods. The first O’Connor Sutton Cronin method is based on a sum of parameters derived from flow charts taken from the Colorado method. The parameters describe general scour vulnerability, left and right abutments and the worst pier conditions, which are all evaluated by relative points. The output of the OCSC method is Vulnerability Ranking Score (VRS), based on which a Priority Rank for all bridges on a single railway line is given. The second Bekić-McKeogh method was developed for Irish Rail on the basis of various standards and policies for scour evaluation. The output from the Bekić-McKeogh method is a Priority Rating (PR), accompanied with the recommendations and a period for the next bridge inspection. Comparison of assessment results by using two methods are presented for 100 railway bridges over the rivers and streams in Ireland. The paper in particular shows different assessment results obtained for three bridges, where results of both methods are compared and analysed in detail.

bridge scour, bridge inspection, scour risk assessment