Question

Q2) A canal of trapezoidal section has bed width of 8 m and bed slope of 1 in 4000. If the depth of flow is 2.4 m and side slopes of the chamel are 1 horizontal to 3 vertical, determine the average flow velocity and the discharge carried by the channel. Also compute the average shear stress at the channel boundary. Take value of Chezy's constant = 55. Q3) 6.11. A power canal of trapezoidal section has to be excavated through hard clay at least cost. Determine the dimensions of the channel, given, discharge equal to 14 m/s, bed slope 1:2500 and Manning's N = 0.02.

Answer 1

Complete solution for question 1 is given below.

Sohition : Given d = 250 mm A a 0.04 m/ 250 c = 52 3 • From figure tan 38 = Ac AC oc 250 . AC = 144.344 mm 6. AB = 288.68 mm * Area of flow x ABxd x 288.68x 250 2 A s 36084.39 mu O AtoB * kletted perimeter P = V AC²4 oc² x 2 p= V 144,342 + 2502 x a P = 577.35 mm

Hydraulic mean depth A 62.5 mm Р ma 0.0625 m A 0.0369 m² * Chezy's equation is given by Q = AC mi 0.04 = 0.0369 x 52 x v 0.0625xi 6.958103 i = 1 in 143.82 :.(Gradient I in 143.82