Experimental Investigation of the Effect of Diameter and Placement Level of Lattice Collars on Scour Reduction around Bridge Pier

oleh: Mohammad Hemati, Nasibeh Gholizadeh, saeideh Dolatkhah

Format: Article
Diterbitkan: Shahid Chamran University of Ahvaz 2016-12-01

Deskripsi

In this research, the effect of lattice collar on reducing scour around the bridge pier was experimentally studied. A series of experiments were conducted in a flume with length of 6m and width of 0.6m. For evaluation of scouring phenomenon a cylindrical pier 60 mm in diameter, four different sizes for collars and three various levels for collars placement were used in clear-water conditions. The results revealed that the minimum scour depth occurred with lattice collars with width of 2.5 and 3 times of the pier diameter (2.5D<sub>p</sub> and 3D<sub>p</sub>) that has been installed at the 0.1D<sub>p </sub>level under the bed, where the maximum scour depth decreased by 73%. Whereas scour depth decreased by 40% due to installation of lattice collars with width of 1.5D<sub>p</sub> and 2D<sub>p </sub>at the 0.5D<sub>p </sub>level under the bed. Also, the result showed that the efficiency of lattice collars was about 20% more than non-lattice. Generally the scour volume around bridge pier at the 0.1 D<sub>p</sub>, 0.5 D<sub>p</sub> and D<sub>p </sub>levelunder the bed decreased by 58%, 60% and 10%, respectively due to lattice collars installation.