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~1 <br />1 <br />1 <br /> <br /> DITCH DESIGN SPREADSHEET <br /> USING MANNINGS EQUATION <br /> FOR TRAPEZOIDAL OR V-SHAPED DITCHES DATE: O1-Feb-89 <br /> GENERAL INFORMATION <br />' PROJECT OR BILLING NO. SAN LUIS 14702 <br /> FEATURE MINE PIT DIVERSIONS (TYPE 4) <br /> DESIGN EVENT: RETURN PERIOD AND DURATION 100 YR 24 HR <br /> FREEBOARD REQUIREMENT (FT} 1.0 <br /> SIZING CRITERIA (INPUT) <br /> DESIGN FLOW (CFS) 185.0 INTERIM CALCS <br /> TRIAL WIDTH (CHANNEL BOTTOM,FT) 8.0 <br /> TRIAL FLOW DEPTH (FT) 4.0 AREA <br /> CHANNEL SIDE SLOPE (H:1), H= 1.0 WET PERIM <br /> CHANNEL LONGITUDINAL SLOPE (~) 0.3 HYD RAD]US <br /> MANNINGS "n" VALUE 0.030 <br />' CALCULATIONS (OUTPUT) <br /> COMMENT <br /> FLOW CAPACITY (CFS} 218.7 OK <br /> MEAN FLOW VELOCITY (FPS) 4.6 <br /> FREE SURFACE WIDTH (TOP WIDTH, FT) 16.0 <br /> TOTAL DEPTH OF CHANNEL (FT) 5.0 <br /> FROUDE NUMBER 0.5 <br /> RIPRAP REQUIREMENT <br /> d50 OF REQUIRED RIPRAP (IN) 0.8 <br />*NOTE: ASSUMED SPECIFIC GRAVITY OF ROCK <br />USED FOR RIPRAP = 2.65 <br /> <br /> <br /> <br />48.00 SQ FT <br />19.31 FT <br />2.49 FT <br />r <br />