Experimental Investigation of Flat, Curved and Angled Submerged Vane's Placement Effect on Bridge Pier Scouring

One of the methods for a local scour countermeasure at bridge piers is the use of submerged vanes. Vanes change the regime of bed load movement that led to control place of deposition and erosion. In this paper the effects of submerged vanes with different forms flat, curved and angled in number (2 and 6) and various configurations (the distance D and located on the pier symmetrically with respect to the flow line) on reducing local scour around cylindrical pier with angle of 20° was performed to investigate. Experiments were conducted in a 10 m long and 0.3 m wide flume and a cylindrical pier of 2.54 cm diameter. Clear-water scour tests with u*/u*c=0.92 were performed. The length of the vanes was equal the pier width and was installed on the bed. Results showed that reduction of scour with different arrays of six vanes was 93%. The highest reduction in scour depth was achieved for curved vanes are placed around the pier.