توسعه زماني مشخصات حفره آبشستگي در اطراف آبشكن ها

Time Development of Scour hole at Around of Abutments

Scour hole development, its time variation and evaluation of its equilibrium state are of great importance in designing and implementing of abutments. Variation of scour hole dimensions and their development have a substantial effect on the scour mechanism. In this research, time variation of scour hole at short wing wall abutments was investigated. The results obtained showed that scouring starts from the upstream corner of the abutment and upstream slope of the scour hole, termed the dynamic angle of repose was found to be 18% greater than the angle of repose of bed sediments. Time variation of scour hole dimensions, namely dimensionless length of scour at upstream, downstream, width of scour with time found to be logarithmic. The relationship between scour depth and time was also logarithmic and 60% of the maximum scour depth took place at the first hour of the experiment. The results obtained also showed a good agreement with other works. .