Author(s): M. Rahman Md; M. A. Haque; H. Nakagawa; Y. Muramoto

Linked Author(s):

Keywords: Local scour depth; Spur-dikes; The Brahmaputra river; Analytical model

Abstract: Features of scouring around spur-dikes in a sand bed braided river are examined and compared with those in the simplified laboratory condition. Some of the available methods for the prediction of local scour around spur-dikes are reviewed in order to evaluate their applicability to the field situation. The study revealed that most of the available methods were developed for vertical-wall spur-dikes and are not useful for structures having side slope gentler than 1V: 1.5H. It was observed from available experimental studies that local scour depth around spur-dikes increased as the value of b/h (b = length of spur-dike in the lateral direction and h = approach flow depth) increased up to a certain limit. Beyond that limiting value of b/h, the observed scour depth remained constant. This phenomenon was not incorporated in most of the available prediction methods. In the present study, an analytical model was modified for the prediction of local scour depth at any range of b/h and side slopes. The developed model then applied to some of the spur-dikes along the Brahmaputra river in Bangladesh.

DOI:

Year: 2003