Author(s): Terunori Ohmoto; Hiroshi Cho; Minoru Miyaka
Linked Author(s): Terunori Ohmoto
Keywords: Bridge pier; Local scouring; Countermeasures; Guide piles; Horseshoe vortex
Abstract: Countermeasures against local scour of piers include protection against riverbed scour or control of horseshoe eddies with strong downstream currents. In Japan, the former is often adopted as a countermeasure for localized scour, and there are research cases in which permeable rubble piers and impermeable protection piers with concrete blocks have been applied around piers. In the latter, there are cases where the shape of the piers is improved to streamline or vanes or piles are installed upstream of the piers, but these have not been studied under systematic conditions, and there are many unknown points. In this study, we focused on the latter, which has a smaller environmental impact, and installed a flow guide structure directly upstream of the piers to suppress the horseshoe vortex around the piers and the downstream flow in front of the piers to reduce scouring of the piers. The experimental results showed that the maximum scour depth around the piers was reduced by about 50% and the volume of scour holes was reduced by about 20% when the flow-conducting structure was installed compared to no countermeasure.
Year: 2024