Laserfiche WebLink
DITCH 18 <br />Manning's Equation <br />Flow In a Trapezoidal Channel <br />DEPTH D 0.75 FEET <br />WIDTH W 3 FEET <br />Slope S 0.2 EXPRESS AS DECIMAL <br />Mannings "N" N 0.04 EXPRESS AS DECIMAL <br />SIDE SLOPE X 1.5 SLOPE = X:1 <br />AREA=(W *D)+(X*D2)= <br />WETTED PERIMETER=(W)+2*[((X*D)2+Dz)~rz] <br />R=AREANVETTED PERIMETER <br />V=(1.49/N)•(Rv3)«(S ~n)= <br />Q=AXV= <br />Q REQUIRED -Peak Discharge <br />Riprap Sizing - Dtich 18 <br />D50 =Size of Riprap <br />D50 = ((V X S^.177.58))^2 <br />D50 =Diameter in feet <br />V =Velocity <br />S =Slope <br />D50 = 1.24 feet 14.8 inches <br />TR-16 17 <br />3.09 Feet2 <br />5.70 Feet <br />0.54 <br />11.08 FUSec <br />34.28 CFS <br />34.23 CFS <br />05/08 <br />