Author(s): Majid Fazli; Masoud Ghodsian; Seyed Ali Akbar Salehi Neyshabouri
Linked Author(s): Seyed Ali Akbar Salehi Neyshabouri
Keywords: River Training; Spur Dike; Scouring; 90° Channel Bend; Bed Topography
Abstract: One of the most commonly method of river bank erosion is use of the spur dikes. Spur dike creates rapid variations in flow, sediment transport and hydraulic geometry of river. The mechanism of flow and sediment discharge in channel bend is very complicated, when a structure like bridge pier, spur dike, and abutment is constructed in it. Most of the previous investigations on the flow behavior and scour around spur dike were carried out in straight flume. In this paper results of experiments on scour around spur dikes under clearwater condition in a channel bend are presented. In order to estimate the influence of spacing and locations of spur dikes on scour, extensive experiments were conducted in a 90° channel bend. Sand with uniform grain size was used as the bed materials. Experiments were conducted by using two spur dikes with four different spaces (2. 6, 5. 2, 7. 8 and 10. 4 times of spur dike length) in three different situations in the bend (the first spur dike Was situated at sections 30°, 45° and 60°). It was found that the location of spur dikes in the bend have important role on shape and dimensions of scour hole. The maximum relative depth of scour was correlated to the space and the location of spur dikes in the bend.
Year: 2007