Discharge Capacity of an Improved Form of Labyrinth Weir

The aggravation extreme weather events have greatly increased the interest in the safety of flood control structures, especially the safety of dams and reservoirs. Non-linear weirs such as labyrinth weirs represent an effective option for improving the safety and resilience of these types of facilities. The labyrinth weir designed with trapezoidal and triangular shape in view plan has been used in research and application for several decades. However, the rectangular plan form can also be a more efficient and cost-effective structure. This study used experimental and numerical modeling to investigate some improvements to the standard labyrinth weir shape. The tested models, three models of rectangular labyrinth weir and two models having trapezoidal shape, were examined in rectangular channel conditions for developed crest length ratios (L/W) equal to 4 and 5. In addition, to verify the potential of the overhangs for the labyrinth weir, three overhang arrangements were tested: with upstream and downstream overhangs (symmetrical); with only upstream overhangs; and, with only downstream overhangs. The obtained results confirmed the performance improvement of this type of weir by the adoption of an improved form of the labyrinth.