Influence of permeable groins with radial arrangement on local scour around groins: an experimental study

ABSTRACT Local scour control around the groins is one of the most important designs and construction factors. In this study, a new radial arrangement style of permeable groins Permeable Groins with Radial Arrangement (PGRA) is introduced and the performance of the groins in this layout is compared to that of the traditional straight arrangement of groins in one and two rows. 90 experiments were performed using permeability of 40%, 60 and 80 per cent and two different discharges. The clear water condition with smooth and homogenous bed sediment materials was considered. The results show that groins arrangement permeability rate and flow discharge affect the sediment conditions around the groins. The most effective arrangement in reduction of scour depth is PGRA with 7 piles in which the scour depth is reduced by 75%, 80% and 66% in permeability rates of 40%, 60% and 80%, respectively.