The effect of relative surface roughness on scour dimensions at the edge of horizontal apron

• 作 者: Parisa Koochak Mahmood Shafai Bajestan
• 机 构: Shahid Chamran University,College of Water Science Engineering,
• 出 处: International Journal of Sediment Research
• 发表日期: 2016年02期
• 关键词: Horizontal apron Bed roughness Scour Rivers

Roughened horizontal aprons are bed covering scour countermeasures constructed downstream of stilling basins and other places where scour hole may develop.In these cases scour occurs at the edge of the apron which can lead to failure of the apron.In the present study,24 experimental tests were carried out on four different aprons with(2,5,10 and 14.28 mm) roughness heights and two different bed material sizes of 0.8 and 1.4 mm under different flow conditions.The results indicated that as the roughness height of apron increases,a significant reduction in the scour depth occurs.

Roughened horizontal aprons are bed covering scour countermeasures constructed downstream of stilling basins and other places where scour hole may develop. In these cases scour occurs at the edge of the apron which can lead to failure of the apron. In the present study, 24 experimental tests were carried out on four different aprons with (2,5,10 and 14.28 mm) roughness heights and two different bed material sizes of 0.8 and 1.4 mm under different flow conditions. The results indicate that as the roughness height of apron increases, a significant reduction in the scour depth occurs.