(Solved): A trapezoidal water conveyance canal is to be designed to convey a discharge of 50m3/sec at a ...

A trapezoidal water conveyance canal is to be designed to convey a discharge of $50{\mathrm{m}}^3/\sec$ at a velocity of $2\mathrm{m}/\sec$. The bed width-to-depth ratio is 0.8 . The side slopes are $1\mathrm{H}:1\mathrm{V}$. Calculate the bed width, depth of flow and bed slope of the channel. Assume Manning's coefficient, $n=0.02$ (15) c) For a homogeneous earth dam $52\mathrm{m}$ high and $2\mathrm{m}$ freeboard, a flow net was constructed and the following results were obtained. $?$ Number of potential drops $=25$ $?$ Number of flow channels (flow lines) $=4$ The dam has a horizontal filter of $40\mathrm{m}$ length at its downstream end. If the coefficient of permeability of the dam is $3\times 10^{?3}\mathrm{cm}/\sec$, i. Calculate the seepage flow per metre length of the dam (5) ii. Calculate the seepage flow per metre if a cut-off with the flow efficiency $E_Q$ of $70\%$ is placed in position on the dam (5) iii. Calculate the head efficiency of the cut-off if the head loss across the cut-off is $35.5\mathrm{m}(5)$