Evaluation of characteristics and zones of flow around spur-dikes constructed on rivers with a wide flood-plaines

Abstract

This study was carried out to evaluate the characteristics and dimensions of different zones of flow, which are formed around spur-dikes due to contraction, which are used to defend riverbanks and coasts. The evaluation of these dimensions will help the designers to protect the opposite bank from scouring The study indicates that there is a relationship between those dimensions and the length of the structure, angle of construction of the structure , width of flood plain and the flow characteristics (Reynold's and Froude's Numbers). The author introduced some empirical formulas to calculate those dimensions which are useful to calculate the dimensions of expansion and contraction zones for spur-dikes constructed on rivers with a compound cross-sections.