Recognising the significance of scour (ie channel erosion, in all its forms) as a cause of bridge damage, a screening methodology for assessing and ranking New Zealand bridges in terms of their susceptibility to scour is presented. The methodology trialled during 1999–2000 comprises an office review of available information, and a field review of the bridge(s). Based on ratings of bridge significance to the roading network and of bridge vulnerability to scour (as indicated by assessments of aspects of the bridge and the waterway), an overall scour-susceptibility rating (1 = highest susceptibility, 4 = lowest susceptibility) is assigned.
Use of the proposed methodology for all bridges of a roading network will enable 'at-risk'sites (of higher scour-susceptibility ratings) to be identified, thereby avoiding potential safety and asset risks. It also enables scour risk to be consistently and rationally evaluated and ranked nationwide through comparison of the overall scour-susceptibility ratings for bridges on the New Zealand state highway network.
Keywords: bridges, bridge scour, bridge screening, design, failure, flooding, New Zealand, risk management, rivers, roads, scour, structures