Prediction of scouring depth at the outlet of partially blocked box-culvert

Culverts are built at a location in waterway cross a road or railway. The narrowing cross section of waterway creates a limitation to flow passage and therefore blockage occurs during flood events with accumulation of debris at the inlet. The blockage of the culvert can accelerate bed scouring and consequently causes failure of the culvert. It subsequently produces high damage to private properties and public assets. This article is concerning scouring at the outlet of partially blocked culverts. In this context the blockage of culverts is studied as an important factor on the scouring pattern of culverts. Therefore, experimental tests were conducted to investigate the effects of culverts blockage on scouring downstream of a culvert. The experimental program was designed to investigate the relationship between the maximum scour depth, blockage ratio of the culvert and flow characteristics. The experimental tests were carried under non-blocked and partially blocked conditions. The sediment material used in this study was uniform non-cohesive sand particles. Results showed that the scoured area and maximum scour depth increases in partially blocked condition comparing with the non-blocked condition. The results were compared with the previous developed models and it was found that the previous model predict scouring depth less than the scouring depth at blocked condition.