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

Hemati, Mohammad; Gholizadeh, Nasibeh; Dolatkhah, Saeideh

doi:10.22055/jise.2016.12500

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

Document Type : Research Paper

Authors

Mohammad Hemati

Nasibeh Gholizadeh

saeideh Dolatkhah

10.22055/jise.2016.12500

Abstract

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_p and 3D_p) that has been installed at the 0.1D_plevel 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_p and 2D_pat the 0.5D_plevel 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_p, 0.5 D_p and D_plevelunder the bed decreased by 58%, 60% and 10%, respectively due to lattice collars installation.

Keywords

Lattice collar

Experimental Study

Scour control

Bridge pier

Level placement