Local Scour at Bridge Abutments

Abstract

This paper presents the results of an experilnental investigation of local scour at bridge abutment models of three common shapes placed in laboratory flume with uniform sand with d)l) =0.775 mm. The 1l1uximum scour depths and extent of scour were determined corresponding to clear water conditions. For design purposes, a general nondimensional equation for clear water scour prediction is proposed. The equation addresses aU the inlportant variables in terms of shape and size of abutment, sediment and flow characteristics. The equation was verified with (he present experimental data as weB as with the data obtained by previous investigators under comparable conditions.