Effect of Cable and Collar on Scouring Depth Around Cylindrical Bridge Pier in Meandering River

The local scour around a bridge pier in recent years has been widely studied by different authors. They proposed different methods to control the scouring depth. Until now, many of authors have studied to find out how to control scouring around a pier along the straight stream. However, it may be required to construct a bridge across a bend of a river due to the some constraints. The objective of this research is to study a scour pattern around such piers on a bend due to the fact that there may be a difference between a flow pattern on a straight stream and the meander. Thus, this study tries to check whether the use of collar and cable together effects on scouring around bridge pier constructed on river meander. The results showed that as cable diameter increases and pitch of helix decrease, scouring depth will be decreased. The reduction of scouring depth by using cable does not exceed from 59% and alone collar reduces scour depth up to 55%. Using collar and cable together is reduced scour depth to 69.7%.