Experimental analysis of open check dams

Check dams are essential hydraulic structures designed to control floods. Closed-type check dams prevent the downstream transport of materials such as woody debris and sediment. However, in certain regions, open check dams, which retain large materials while allowing smaller particles to pass, are preferred. This study aims to experimentally compare the trapping capacity of two open check dams with different void ratios in retaining woody debris. The study evaluates the results of experimental tests conducted under two different discharge conditions to determine the trapping efficiency of these structures. Bent-2 generally exhibits a higher trapping capacity compared to Bent-1. For short-sized woody debris, the trapping efficiency of Bent-2 was measured as 40.1% at Qm50 discharge and 36.4% at Qm500 discharge, whereas Bent-1 exhibited a significantly lower capacity of 3.0% at Qm50 and 6.4% at Qm500. For long-sized woody debris, Bent-2 maintained a consistently high trapping capacity of approximately 85% across both discharges, while Bent-1's capacity was 52.4% at Qm50 and 39.2% at Qm500. Bent-1 demonstrated lower efficiency for short woody debris but exhibited a higher trapping capacity under Qm50 discharge for long woody debris. In contrast, Bent-2's trapping capacity remained relatively stable across different discharge conditions. Additionally, an increase in trapping capacity was correlated with a rise in water levels, with higher water levels observed in Bent-2 experiments. Overall, although Bent-2 generally outperforms Bent-1 in terms of trapping efficiency, its direct application to all flood-prone basins may not always be appropriate. The selection of the check dam type should be based on site-specific evaluations.