الفهرس Only 14 pages are availabe for public view
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Abstract
Local scour is one of the most important problems affecting the stabi1i1.y of hydraulic structures which are commonly constructed in alluvial bed ~s. Local scour occun due to disturbance of the flow issuin8 from 1be hydraulic structure with high velocity. Therefore, the flowing water downstream hydraulic struetureS must be dissipated to achieve tranquil flow conditions as the flow enters 1be downstream cNPmeI•
In the present study, stepped weir (with one step) is recommended to dissipate the water energy downstream the weir. Experimarta1 work is carried out to suggest dimensions of 1be step lqtb, the step height, and the step end sill height which give maximum water
energy dissipation, and give minimum scour hole dimensions.
Results indicate that the ’suggested stepped war possesses a great efficiency in dissipating the water energy and reducing the scour hole dimensions than that in case of normal weir. Results also show that with decreasing the relative step It’lJ8lh and irk.a~ the relative step height the scour hole dimensions decreaed. and use of step end sill produces a good
efficiency in reducing the scour hole dimensiom.
A nine formulae wen Q\ttained for 1be relationships of maximum scour depth. position of maximum scour hole depth from the floor end, and maximum scour hole . length using
regression analysis.