Laboratory study of reducing the scour depth downstream of Calvert with a square cross section adjacent to the floor

Protection of the downstream of culvert outlets against scour process, as a water conveyance structure, is a highly significant issue in design of culverts. In this study, the effect of bed litter length on downstream scour depth is investigated. For this purpose, experiments were carried out on the laminate with different lengths. According to the results, the particle landing at 22%, 33% and 66%, respectively, and the landing at particle landing of 2.5%, respectively. 15%, 20%, and 40% decreased particle depth by 20%, 25%, and 31%, respectively, indicating that bedding has a positive effect on decreasing downstream scour depth. The scour for the flooring considering the length of the layer showed that the scour depth decreases with the increase of the layer length due to the constant landing number.