عنوان مقاله [English]
نویسندگان [English]چکیده [English]
One of the aquatic structures used for protecting erodible channel beds is serial step- pools. These steps are exposed to danger of scouring similar to the vertical drops structures. The purpose of this paper is to evaluate scouring rate downstream of the step- pools. For such a task, the laboratory flume was used. The experiments were conducted providing steps with vamp slope angles of 0°, 20°, 30° and 40°, and discharges of 10, 20, 30, 40 and 50 liters per second with flume slopes of 1%, 2% and 3%. The results showed that by installing vamp segment on the steps with slope angle of 40°, the maximum depth of downstream scouring in comparison with base case (step without vamp) is decreased by 41%, 15% and 21% for flume bed slopes of 1%, 2% and 3%, respectively. Also, these results denote that installation of a vamp on the steps caused location of maximum scouring depth moving significantly toward downstream helping step stability. Based on the results of this paper, it is declared that using vamp segment on the step, increases the pool- step efficiency for protecting erodible channel beds.