Reducing the maximum scour depth downstream of the sluice gate using a combination of two buried plates with a sill

Abstract

One of the main interests of researchers is the local scour downstream hydraulic structures due to free hydraulic jump, which can cause massive damage or collapse for hydraulic structures. In this study, a new countermeasure was developed to reduce the maximum scour depth by using two buried plates and a sill downstream of the sluice gate. The results showed that the two buried plates were a very effective tool in reducing the maximum scour depth downstream of the fixed apron. It was found that when the two plates were buried at (LP1/LB = 0.07 with LP2/LB = 0.14) with a sill installed at (LS/LB = 0.1 with hS/LS = 0.14), the maximum scour depth upstream and downstream of the first plate (Ds1 and Ds2) was reduced by 57% and 64%, respectively, and the maximum scour depth downstream of the second plate (Ds3) was reduced by 35% compared to the maximum scour depth for the no-plate condition. An empirical formula was developed to determine the maximum scour depth. The study results may be applied in the area of protection design for the fixed apron.