An experimental investigation of upstream ramp effects on sediment ingestion and hydraulic performance of trench weirs with flat bars

This study presents an experimental investigation on the ingestion of sediment into trench weirs with flat bars, incorporating the effect of a ramp-positioned upstream of the channel. The research examines the influence of varying ramp angles (θ = 10°, 15°, and 20°), heights, and a constant slope on the flow dynamics and sediment transport over and within the trench weir. A relationship is developed to quantify the amount of sediment entering the trench under different hydraulic and geometric conditions. The findings indicate that the bed load of the stream interacts with the trench weir, leading to sediment entrapment between the bars, which subsequently reduces porosity and alters discharge characteristics. The study highlights the clogging effect caused by sediment accumulation and its impact on the efficiency of the weir. The results provide insights into optimizing ramp height and slope to minimize sediment ingestion, thereby improving the performance and longevity of trench weirs.