Monitoring Countermeasure Performance Using Sonar

Current policy in the US considers riprap placed at bridge piers to be only a temporary countermeasure against pier scour. Federal guidance requires that riprap placed at bridge piers to be monitored periodically by visual inspection or by fixed instruments. This policy stems from the challenge in adequate sizing of riprap to withstand the turbulence and hydraulic stress generated in the vicinity of a bridge pier under flood-flow...