Investigation of Local Scour and Flow Field Around Bridge Pier with and Without Collar Through Numerical Simulation

Localized scouring is an inevitable phenomenon that erodes the sediment bed surface in the surrounding areas of the pier. Adopting suitable scour protection countermeasures to mitigate the scour is a challenging issue for maintaining the stability of the bridge. This paper numerically studies the localized scouring that occurs around a circular bridge pier and the effect it has on the use of collar plate as scour protection device. The flow field around an unguarded pier and a pier guarded using a collar plate is investigated through numerical simulation. The LES turbulence model is employed for simulating transient phenomena. The Soulsby White House equation is used to compute the critical dimensionless shear stress. Vectors of flow patterns around the scour hole formation are also studied. The numerical results show that using a collar as a scour protection device is able to reduce scour depth by nearly 87.71%. Results of the 3-dimensional numerical model suggest that numerical simulation based on computational fluid dynamics has turned into a promising way to deal with bridge scour.