Effect of Bridge Pier Geometry on Local Scouring

Local scour around bridge pier is the main reason for failure of a hydraulic structure like as bridge piers, abutment etc. Local scour around a bridge pier is largely depending on the shape of the bridge pier and how the design is fashionable from the view of construction. Local scour is a complex phenomenon which depends on the discharge, depth of flow, geometry of the pier and type of sediment particle. In this study, geometry i.e. shape of the pier is the main concern. Research is carried out by considering three different geometry pier of rectangular, circular and oblong shape to conclude the optimal shape of the pier at a different flow velocity of 0.146 m/s, 0.231 m/s & 0.323 m/s on 15 m hydraulic flume under clear water condition using natural sand as the bed material in the university laboratory. Results show an idea that the scouring at the upstream face is directly proportional to the exposed upstream nose area of the pier. It is also shows that the scouring is highest in all cases for the rectangular pier and minimum for the oblong pier.