investigation of control methods on local scouring around the bridge piers

scouring is the removal of sediment particles resulted from variations of flow pattern. local scour is considered among the reasons of instability and ultimately failure of bridges. during the past decades, different methods were proposed against local scour at bridge piers. these methods can be broadly classified into two categories: flow-altering and bed-armoring methods. each method can be classified into different groups based on their shapes and performances. in this paper, a comprehensive investigation on the studies of various methods against local scour, combination methods in experimental conditions and limitations in field applications were carried out. also, suggestions were presented for further research on selecting methods for controlling local scour around bridge piers.