Article

M. Aman, Zakir Hussain College of Engg & Tech.; M. Athar ,Zakir Hussain College of Engg & Tech.; I. S Saluja ,Zakir Hussain College of Engg & Tech.; H. Athar ,Zakir Hussain College of Engg & Tech.

This paper presents the experimental investigations of effect of bend on scour and deposition patterns around causeways and bed bars. Data have been collected in a re-circulatory open channel flow system on three causeway model slabs for many discharge values ranging from 1.0 l/s and 8.0 l/s. The causeway model slabs were made of cement concrete with 0.75 m length, 0.20 m width and 0.20 m in overall depth. To critically observe the effects of presence of bend on scour and deposition, three locations of causeway slabs and one location of bed bar were used. The first one is provided in a straight reach in the test channel, second one just after the first bend normal to flow and third one was an oblique slab provided between the inner and our curvature of the second bend downstream of the first bend. Data of scour and deposition around causeways and bed bar were recorded after the end of the run. Also photographs were taken. It is concluded that for each discharge, scour and deposition occur in all cases, but at low flow the scour in straight reach is less pronounced. However, scour occur in second and third causeways due to the presence of bends. At still high values of discharges, scour and deposition both are significant in all the causeways. Since first causeway is straight and normal to flow, there is uniform scour and deposition along the edges of the causeways. The scour and successive deposition occur in other two causeways with high magnitudes but the location of maximum scour depth shifted. Also scour holes were observed around the bed bars. Photographs also support the findings in this investigation.