Bridge Failure Prevention: An Overview of Self-Protected Pier as Flow Altering Countermeasures for Scour Protection

The inherent scour process around the bridge piers needs to be considered and crucial to ensure a sustainable and economical bridge design. The performance of any scour protection/controlling devices around bridge piers is determined on how each device counters or minimize the scouring process. Besides the usually adopted bed armouring, abundant studies have been conducted to evaluate the efficiency of flow-altering countermeasures in reducing local scour depth. The flow changes due to the rigid pier are modified in a way to reduce the impinging effect on the bed. This paper discusses on the performance and feasibility of self-protected piers, defined as a pier without any additional structure built either next to or at a distance away from the pier. We paid attention to the efficiency of the proposed countermeasures in terms of possible maximum scour reduction and provide the best configuration of each self-protection pier. This review consists of analysis on the openings on pier including internal tubing, slot and pier groups, and modified pier shapes as the flow-altering, self-protected countermeasure alternatives.