Published Paper Details:

Safety of a bridge depends on the depth and volume of local scour around its piers. The existence of parallel railway-bridge and road-bridge or a newly constructed bridge by the side of an old bridge gives rise to a situation, where the interference of the presence of an upstream pier and a downstream pier is prevalent. The upstream pier could primarily influence the scour at a downstream pier in two ways: (1) upstream pier modifies the flow field in the wake flow region that acts as an approaching flow for the downstream pier to scour and (2) the sediment that is scoured from the upstream pier is being fed to the scour hole at the downstream pier. The present study attempts to quantify the effect of the mutual interference of upstream and downstream piers on local scour at both the piers. The mutual interference of the piers on local scour depends on the shape of the piers, flow velocity, flow depth, sediment size, and oblique distance between the piers and flow oblique angle The study deals with an experimental study of local scour around two inline piers accomplished by measuring the equilibrium scour depths in clear water scour in carefully designed and controlled experiments in the laboratory. These studies were accomplished by measuring equilibrium scour depths in clear water scour in care-fully designed and controlled experiments in the laboratory. The results reveal that the equilibrium scour depth at rear pier increases as the distance between rear and upstream piers increases. The scour depth at the rear pier is approximately 70-80% of the scour depth at the front pier. However, the equilibrium scour depth at upstream pier is independent of streamwise spacing between the piers. Similarly, for spacing between front and rear piers is more than 7 times the rear pier diameter, the equilibrium scour depth at upstream pier is independent of spacing between them.