SERVICE ROAD AND DOWLA A service road is provided usually on the left bank of the channel. In case of very small channel i.e. minor, it may or may not be provided. The top width of the bank carrying service road should not be less than 5 m. According to CWPC minimum road width should …
FREE BOARD The vertical distance between F.S.L. and top of the lowest bank of the channel is know free board. It is provided to prevent waves or fluctuations in water surface from overtopping the banks. Freeboard depends upon the canal size, wind action, soil characteristics and location. According to USER, free board may be worked …
SIDE SLOPE The side slope of the canal depends upon the type of soil. The canals in alluvial soils are designed assuming a 1/2 :1 side slope, irrespective of the actual initial side slope. It is assumed that after the due course of a run, the canal section would ultimately acquire a 1/2: 1 slope. …
CHANNEL CROSS-SECTION The channel sections for an irrigation canal may be of the following four types. 1. Canal in cutting. 2. Canal in filling. 3. Canal in heavy filling. 4. Canal partly in cutting and filling. 1. Canal in Cutting. This canal does not require any bank as F.S.L. lies below the G.L. If F.S.L. …
BED WIDTH AND DEPTH RELATIONSHIP Kennedy’s theory does not give any importance to B/D ratio. The very large number of sections with varying B/D ratio and all satisfying the C.V.R. are possible by this theory. But all these sections cannot be equally satisfactory. This drawback of Kennedy’s theory was made good to some extent by …
DESIGN OF THE CANAL In the design of a canal one has to find out bed width (B) depth (D), longitudinal slope (S), and velocity of flow (V). If discharge (Q) and silt factor (f) are given, the method of finding. This aspect limits only finding the sectional dimensions of the canal. But how to …
LONGITUDINAL SECTION OF A CANAL The points which should be consider in fixing alignment of the canal. Actually, the whole of the area where irrigation is propose, is surveyed, and contour plans prepared. The other features of the area are also marked over the plans. The contour plan on which other features of the area …
TRACTIVE FORCE THEORY In the study of mechanics of sediment transport, the soil particles are always considered as incoherent. Most of the river beds are made up of sand and gravel and as such assumption in regard to soil being incoherent is correct. The basic mechanism that controls the sediment transport, is the drag force …
PRACTICAL ASPECTS OF BED FORMATION The bed of the channel in which water is flowing, may adopt various shapes depending upon the velocity of flow. At very low velocity of flow, bed of the channel does not move at all. When velocity is slowly increased a stage is reached when the sediment load is just …
SEDIMENT TRANSPORT A flowing water in a channel, always tries to scour its surface. Silt, gravel or even larger boulders are first detached from its bed or banks, and then swept D/S by moving water. The phenomenon of detaching and then sweeping The silt or gravel from bed or banks is know is sediment transport. …
