Author(s): Hassan Falahat; Mohammad J. Ostad Mirza Tehrani

Linked Author(s):

Keywords: Reservoir sedimentation; Sustainability; Pressurized flushing; Flushing half-cone

Abstract: Sedimentation reduces the operability and sustainability of dam reservoirs, and has been an issue for operators and owners. The dam outlet may be blocked by deposited sediments and the reservoir may be inoperable. Pressurized flushing has been revealed as one of the most efficient techniques for removing deposited sediments in the vicinity of the outlet. This efficiency may be evaluated by the volume of the halfcone which depends on various factors namely the water and sediment level, the geometry of the reservoir, the discharge of the outlet, and the properties of the deposited sediments. This paper discusses the results obtained from physical laboratory tests, conducted systematically with varying outlet diameter, water and sediment heights to investigate the different parameters and their rules. A part of analysis revealed that considering the sediment height relative to the outlet lower level gives a better understanding of its impact on the volume of pressurized flushing half-cone. This conclusion may be drawn implicitly from the previous studies, consolidating that the increase in water and sediment heights, results in a larger half-cone of pressurized flushing. Consequently, the results illustrate that the higher the level of water and sediment is above the outlet lower sill, the larger the volume of flushing half-cone may be obtained. However, it should be noted that the sediment height and outlet diameter respectively play a more direct role in the formation of halfcone erosion, rather than the water height.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p1466-cd

Year: 2023