Local Scouring around Twin Bridge Piers in Open-Channel Flows

Laboratory experiments were carried out to investigate local scouring around twin cylindrical piers in open-channel flows. The experimental results of clear-water scouring around the twin piers show that the scour hole formed around the upstream pier at different pier spacing was almost the same as that around an isolated pier. However, the local scour depth around the downstream pier was less than that around the upstream pier. The local scour depth around the downstream pier with the velocity can be segregated into four regions: a no-scour region, synchronous-scouring region, transition region, and a radical-deviation region. Finally, a relationship between the deviation in the radical-deviation region and the spacing of the two piers was obtained.