Experimental Investigation of Scouring Around the Coastal Pier with the Triangular Structures

Scouring is a natural phenomenon that occurs as a result of the erosive factor of water flow. Due to the impact of water on the base of the pier, vortices called horseshoe vortices are formed. Horseshoe vortices are more active in front of the base, which is the main cause of scouring. In this study, the effect of using triangular structures on reducing scour around the pier bases was investigated in a laboratory. This research was used in a laboratory flume with a 90-degree arc. Triangular protective structures with angles of the 15, 30, 45 and 60 degrees and a curved triangular structure were considered. Experiments were performed at the 6, 7.5, 8.5 and 10 liters per second. The results showed that the installation of triangular protective structures at a maximum flow rate of the 10 liters per second, can reduce the scour depth flow up to 84 and 78 percent, respectively, upstream and downstream. The best performance is for the 15° upstream protection structure as well as the 60° downstream protection structure. The results show that the scour depth increases with increasing landing number. Also, the curved protective structure had a benign performance current upstream and a lower performance current downstream than other protective structures.