Study on Splitters Effect on the Extent and Slope of The Scour Hole Downstream of Overflow Spillways

Document Type : Research Article


Professor of Hydraulic Engineering, Dept. of Civil and Environmental Eng., Amirkabir University of Technology, Tehran, Iran.


Scouring downstream of overflow spillways is an important factor in the design of plunge pools and tail-pond dams. One of the methods to reduce scouring of falling jets is employing splitters on overflow spillway. Splitters cause the falling jet to expand and entrain air. As a result, the jet strength for scouring reduces. In the present work the scour hole extent and slopes located downstream of an overflow spillway with or without splitters is studied in a large hydraulic model with 6 m height. Experiments were conducted with different discharges and tail water depths. It was found that splitters reduce the scour hole slopes as well as the scour extent (width and length). Experiments show that with splitters the maximum width and length of the scour hole reduced by 17% and 20%, respectively. It was also concluded that with splitters, the ratio of scour hole length to its depth increased by 12% and the ratio of scour hole width to its depth increased by 14%. It was also observed that the scour hole slopes reduce in all experiments when splitters are present.


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Volume 9, Issue 4 - Serial Number 94
February 2015
Pages 15-24
  • Receive Date: 30 April 2015
  • Revise Date: 17 July 2015
  • Accept Date: 29 August 2015
  • First Publish Date: 29 August 2015