Mohammad Vaghefi

With the advancement in the science of engineering, bridge piers scouring has become a well-known phenomenon, and engineers have always been making efforts to counter such a destructive phenomenon. One of the methods used to reduce scouring around the bridge pier is application of other hydraulic structures which influence the amount of scouring in the flow path, such as submerged vanes, collars, riprap, and spur dike. This study aims to analyse the efficiency of rigid T-shaped spur dike in decreasing the scouring around bridges with a 90° pier in a 180° channel with a sharp bend. Experiments were carried out with the installation of a spur dike at the upstream pier on both inner or outer banks, in different positions, under clear water conditions, and the efficiency of the spur dike for reducing the scouring was compared with the control experiments. The results showed that the installation of the T-shaped spur dike on the outer bank significantly augmented the bridge pier scour reduction, and the greatest influence resulted from installation of a spur dike at 70° position on the outer bank, which reduced the scouring by 50% compared to a case of no spur dike installed.