Investigation of flow characteristics in gabion stepped weirs

Abstract Weirs are used to control and regulate the flow in open channels. In gabion structures, conditions more complex due complexity of through porous body a gabion. The present study aims investigate water surface profile, overflow velocity both through-flow ratios. Six physical models three downstream slopes (V:H 1:1, 1:2, 1:3) two types rockfill (crushed stone rounded gravel) were investigated. Results show that for same discharge, milder slope model (1:3) shows higher than steeper (1:1) with about 9 8% on average respectively. was 60% lower steps upper at nappe regime. Moreover, low porosity slightly depth all sections. Furthermore, increasing from 0.38 0.42 led 27% increment ratio. Finally, four relationships developed estimate ratios upstream inner sections weir. suggested can be considered novel relationships.