The widespread failure of bridges due to pier scour, resulting in significant human toll and huge financial costs, highlights the need for improved scour protection methods. This research investigates the effectiveness of a novel scour prevention countermeasure, F-jacks, in mitigating pier scour. Two experimental scenarios, loose bed and rigid scoured bed, were investigated. Velocity components were measured at 3426 points using an ADV velo- cimeter. Furthermore, a laser meter recorded the bed topography with a 2 cm × 2 cm mesh size. The influence of coverage area (C), installation height (DP), and various hydraulic conditions (U/Uc of 0.81, 1, and 1.28) on the performance of the F-jacks layer in controlling scouring were considered. Where U and Uc represent the depth- averaged flow velocity and the critical velocity of approach flow for sediment motion initiation. The F-jacks layer is more efficient with a C2 (dense) layout than a C1 (non-dense) layout. The C2-protected pier exhibited a substantial reduction in dse/D of approximately 77% at U/Uc = 1 and DP/D = 0.42, and 55% at U/Uc = 1.28 and DP/D = 0.21 compared to an unprotected pier. Here, dse represents the equilibrium scour depth. Given the effective performance of this new technique in controlling scour around bridge piers compared to other coun- termeasures, this paper lays the groundwork for further investigation of the proposed technique as a potential solution to pier scour.

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