سیدشاکر هاشمی

Every year thousands of bridges around the world are destroyed by scouring around their piers. One of the methods to control and protect the piers against scouring is to use submerged vanes. The purpose of this paper is to investigate the effect of upstream submerged vanes on scouring around the bridge pier and bed topography changes. For doing experiments, a cylindrical bridge pier and several numbers of submerged vanes with various angles and lengths were used in a laboratory flume with a 180-degree sharp bend. The results illustrate that by using 3 submerged vanes, sediments have progressed less towards the downstream. Moreover, the surrounded rectangle on scour hole around the bridge pier has the largest and smallest dimensions in test with 4 submerged vanes, length of 1.5 times the pier diameter and angle of 35 degrees relative to the tangent at the bend mid-section, and in a test with 2 submerged vanes, length of equal to the pier diameter and angle of 15 degrees, respectively.