Experimental Investigation of Hockey groyne Length, on Scouring at Straight Channel

One of the regular methods for stabilizing and protecting the riverbanks is use of groyne structure. Groynes alter flow direction to the main axis of the river resulting sediment deposition and stabilization of river sides. Therefore, scour around the groyne and the effect of nose on scour are important parameters in river engineering. It should be noted that change of flow pattern in river side is an affective factor on the rate of scouring around the groyne nose. In this study, the effects of the hockey groyne length (L) on scour in straight channel has been investigated through experimental tests. The results showed that there was a direct relation between scour hole dimensions (including the maximum scour depth (ds), the length of scour hole in up and downstream and the maximum scour width) and hockey groyne length. Also, scour hole distance the from channel wall was longer in hockey groyne comparing to that in straight groyne which prevent from scour in river bank and stabilizing the groyne structure. Thus, maximum scour around the hockey groyne was less than that straight groyne around due to suitable flow direction to the downstream.