SAVING UP TO 100 MILLION DOLLARS PER YEAR BY MITIGATING BRIDGE FLOOD DAMAGE

THE EROSION OF THE RIVER BED AROUND BRIDGE PIERS IS COMMONLY KNOWN AS LOCAL SCOUR AND IS INDUCED BY THE RECIRCULATING JUNCTURE FLOW AT THE INTERSECTION OF THE PIER AND THE RIVER BED. BRIDGE FAILURE CAUSED BY THIS PHENOMENON HAS LONG BEEN AN IMPORTANT ISSUE WITH RESPECT TO BOTH PUBLIC SAFETY AND MAINTENANCE COSTS. AVERAGE TOTAL LOSSES FROM THE RESULTING DAMAGE CAN RUN UP TO A HUNDRED MILLION DOLLARS ANNUALLY. NEARLY HALF A MILLION BRIDGES NATIONWIDE ARE POTENTIALLY AFFECTED BY LOCAL SCOUR. A ROBUST PROTECTIVE SYSTEM THAT CAN BE RETROFITTED TO EXISTING BRIDGE PIERS TO MITIGATE THE SEDIMENT TRANSPORT IS NEEDED. RESEARCHERS HAVE MADE CONSIDERABLE PROGRESS IN DESIGNING LARGE-SCALE FLOW MODIFICATION DEVICES BASED ON THE RECENT DEVELOPMENTS IN VORTEX CONTROL TECHNOLOGY. THE EFFORT ADAPTS THESE TECHNIQUES, TOGETHER WITH THE APPROPRIATE APPLICATION OF SCALING AND BOUNDARY LAYER ANALYSES OF THE VORTICAL FLOW NEAR THE RIVER BED, TO THE DEVELOPMENT OF VORTEX ALLEVIATION SYSTEMS FOR LOCAL SCOUR MITIGATION. VARIOUS DESIGNS ARE BEING TESTED EXPERIMENTALLY WITH SUB-SCALE MODELS TO DEMONSTRATE THE POTENTIAL OF THESE VORTEX ALLEVIATION TECHNIQUES IN MITIGATING LOCAL SCOUR.