Scour is one of the natural phenomenon that take place around bridge piers in any waterway. This increases of the project costs and requires more attention. Alternative scour reduction techniques are needed to minimize the scour. One of these techniques is using a collar around the bridge pier. This research is concerned with the non-cylindrical piers type as this type is commonly used. Also, only few studies are concerned with the scour around non-cylindrical piers.
The objective of this study is to investigate the effect of a collar on reduction of maximum local scour depth around a non-cylindrical bridge pier. An experimental work is done using different applications of the collar along the pier and the scour depths are observed in each case. The analysis of the measured results are use to indicate the optimum position of the collar where the maximum reduction in the scour depth is achieved.