Laserfiche WebLink
4. MOUND SIZING <br /> A. Calculate Clean Sand Lift: 3 feet minus Depth to Limiting Condition (1.C)=Clean Sand Lift (1 ft minimum) <br /> 3.0 ft - 1.3 ft = 1.7 ft <br /> B. Calculate Upslope Height:Clean Sand Lift (4.A)+media depth (1 ft.)+cover (1 ft.)=Upslope Height <br /> 1.7 ft + 1.0 ft + 1.0 ft= 3.7 ft <br /> 0.34:Slope Multiplier Table <br /> Land Slope% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 <br /> Upslope 3:1 3.00 2.91 2.83 2.75 2.68 2.61 2.54 2.48 2.42 2.36 2.31 2.26 2.21 2.17 2.13 2.09 2.06 2.03 2.00 1.97 1.95 1.93 1.91 1.89 1.87 1.85 <br /> Berm Ratio 4:1 4.00 185 170 157 3.45 3.33 3.23 3.12 3.03 2.94 2.86 2.78 2,73 2.62 2.55 2.48 2.41 2.35 2.29 2.23 2.18 2.13 2.08 2.03 1.98 1.93 <br /> Land Slope% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 <br /> Downslope 3:1 3.00 3.09 3.19 3.30 3.41 3.53 3.66 3.80 3.95 4.11 4.29 4.48-4.69 4.95 5.24 5.55 5.88 6.24 6.63 7.04 7.47 7.93 8.42 8.93 9.46 10.02 <br /> Berm Ratio 4:1 4.00 4.17 4.35 4.54 4.76 5.00 5.26 5.56 5.88 6.25 6.67 7.14 7.69 8.29 8.92 9.57 10,24 10.94 11.67 12.42 13.19 13.99 14.82 1547 16.54 17.44 <br /> Select Upslope Berm Multiplier <br /> (based on land slope): 2.42 (figure D-34) <br /> D. Calculate Upslope Berm Width:Multiplier (4.C)X Upslope Mound Height (4.B)=Upslope Berm Width <br /> 2.42 ft X 3.7 ft = 9.0 ft <br /> E. Calculate Drop in Elevation Under Bed:Bed Width (2.B) X Land Slope (1.D): 100=Drop (ft) <br /> 10.0 ft X 9.00 % : 100= 0.90 ft <br /> F. Calculate Downslope Mound Height:Upslope Height (4.B)+Drop in Elevation (4.E)=Downslope Height <br /> 3.7 ft + 0.90 ft = 4.6 ft <br /> G Select Downslope Berm Multiplier <br /> (based on land slope): 5.18 (figure D-34) <br /> H. Calculate Downslope Berm Width:Multiplier (4.G)X Downslope Height (4.F)=Downslope Berm Width <br /> 5.18 x I 4.6 I ft = 24.0 ft <br /> I. Calculate Minimum Berm to Cover Absorption Area:Downslope Absorption Width (3.B or 3.C)+4 ft. =ft <br /> 16.0 ft + 4 ft = 20.0 ft <br /> J. Design Downslope Berm =greater of 4H and 41: 24.0 ft <br /> K. Select Endslope Berm Multiplier: 3.00 (usually 3.0 or 4.0) <br /> L. Calculate Endslope Berm (4.19 X Downslope Mound Height (4.F)=Endslope Berm Width <br /> 3.00 ft X 4.6 ft = 14.0 ft <br /> M. Calculate Mound Width: Upslope Berm Width(4.D)+Bed Width (2.B)+Downslope Berm Width (4.J)=ft <br /> 9.0 ft 10.0-1 ft + 24.0 ft = 43.0 ft <br /> N. Calculate Mound Length:Endslope Berm Width (4.L)+Bed Length (2.C)+Endslope Berm Width (4.L)=ft <br /> 14.0 I ft + 38.0 7 ft + 14.0 ft =I 66.0 Ift <br />