Using Nanostructures to Control Local Scour of Bridge Piers for Steady and Unsteady Flows

Local scour is one of the well-known reasons causing instability of bridges, leading to fracture. Reasons reducing the scour depth in the vicinity of bridge piers are of utmost importance. There are many solutions proposed to decrease the scour depth of bridge piers. In this paper, a non-structural and eco-friendly solution is proposed to reduce scour by using nanostructured materials due to their water resistance. These materials are sediments around the base of the bridge mixed with a material referred to as nano-clay. Experiments were undertaken to investigate the scour of a bridge pier 35mm in diameter in a 10m long and 0.4m wide channel, which has a slope of 0.001. With the concentration of 1% of nano-clay in the floor sediments, the experimental results indicated a decrease in scour depth by 44.23% for steady flow and by 63% for unsteady flow. The minimum decrease in scour depth obtained is 41.6% and 56% for steady flow and unsteady flow, respectively.