Laserfiche WebLink
Ditch F21 -1 <br />Manning's Equation <br />Flow In a Triangular Channel <br />Depth D 0.8 Feet <br />Width W 0 Feet <br />Slope S 0.3 Express as Decimal <br />Mannings "N" N 0.04 Express as Decimal <br />Side Slope X 2 Slope = X:1 <br />AREA= (W *D) +(X *D ^2)= 1.16 FEET ^2 <br />WETTED PERIMETER= (W) +2 *[((X *D) ^2 +D ^2) ^0.5] 3.40 FEET <br />R= AREA/WETTED PERIMETER 0.34 <br />V= (1.49/N) *(R ^.667) *(S ^.5) = <br />IQ =AXV= <br />REQUIRED - Peak Discharge <br />lRiprap Sizing - Ditch F -21 -1 <br />D50 = Size of Riprap <br />D50 = ((V X S ^.17)/7.58)) ^2 <br />D50 = Diameter in feet <br />V = Velocity <br />S = Slope <br />D50 = 1.14 feet <br />9.94 FT /SEC <br />11.48 CFS <br />11.09 CFS <br />14 inches Use 12" Rock <br />TR -81 App. B -54 09/13 <br />