الفهرس | Only 14 pages are availabe for public view |
Abstract DROP structures are widely used in open channels. Downstream the DROP, sudden change from position energy takes place. Also, hydraulic jumps, high turbulence, and air entrainment occur as the flow changes from supercritical just downstream the DROP to subcritical at the tail section. Scour hole is formed in the movable bed due to all these changes in flow characteristics resulting in big increase in bed shear. A laboratory experimental study was conducted to examine the effect of time, flow parameters and the DROP slope on the scour hole dimensions. The dimensions under study are the maximum scour depth, the length of the scour hole, and the scoured volume. Four DROP slopes were examined S= 0:1, 1:1, 2:1, and 3:1. Soil concrete apron was constructed on the low level downstream the DROP. Also, a case with no DROP was used for the purpose of comparison. The resulting data was discussed through figures and statistical equations using hydraulic principles Statistical equations relating the scour parameters (depth, length, and volume) to time were concluded, and were found to be in a logarithmic form. It was concluded that the maximum relative depth of scour increases as the DROP slope gets milder, while relative length of scour and relative volume of scour increase as the slope gets steeper. |