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Workshop 1 Signal Conditioning Circuit Design

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									Drainage System
Design and Layout
      Design Process Flowchart
   Background
                                          Determine Drain
    Information           Select DC,
                                               Sizes
(Soils, Topo, Crops)       Spacing
                           & Depth

     Drainage
      Needed                              Installation
                       Develop System
NO
                           Layout

     Confirm
      Outlet           Determine Grades
NO                          & Depth
      Design Process Flowchart
   Background
                                          Determine Drain
    Information           Select DC,
                                               Sizes
(Soils, Topo, Crops)       Spacing
                           & Depth

     Drainage
      Needed                              Installation
                       Develop System
NO
                           Layout

     Confirm
      Outlet           Determine Grades
NO                          & Depth
Drainage Outlets
Design Curves
                Outlet channels designed
                according to Curve B will
                provide excellent
                agricultural drainage in
                Illinois. Use this curve for
                drainage of truck crops,
                nursery crops, and other
                specialty crops. Designs
                based on curve B will
                provide the best drainage
                that can normally be
                justified in agricultural
                areas.
   Design Curves

Channels that are
designed according
to curve C will
provide good
agricultural drainage
in Illinois. This curve
is the one most often
recommended for
drainage of Illinois
cropland
Drainage Outlets
                   Designs based on curve D
                   provide satisfactory agricultural
                   drainage as long as frequent
                   overflow does not cause
                   excessive damage. This curve is
                   generally recommended for
                   pasture or woodland. It may also
                   be adequate for drainage of
                   general cropland in northern
                   Illinois, provided that the
                   landowner carries out an
                   excellent maintenance program.
                   Designs based on curve D
                   provide the minimum amount of
                   drainage recommended in
                   Illinois.
              Design Curves
          Drainage                CFS/      Acre In/Day
          Curve                   100 Acres (Drainage Coefficient)
            B                      20                      4.8
            C                        8                     2.0
            D                        5                     1.2

For comparison: For a 100 acre watershed, RCN = 75, Avg. Slope = 1% in Central Illinois
                A 2 Yr., 24 Hr. Rainfall yields 1” of Runoff and would result in a Peak
                Flow of 30 CFS.
                A 10 Yr., 24 Hr. Rainfall yields 2” of Runoff and would result in a Peak
                Flow of 70 CFS.
  Ditch Configuration




 Once you know what the capacity of the outlet channel must be,
 you need to determine the size that will enable it to convey the
 desired amount of flow without letting the water surface rise
 above a predetermined elevation. The following sections describe
.
 some basic hydraulic concepts that will help you design a channel
 of the proper size
     Outlet Ditches
                                                                        Maximum Velocity
Velocity                                      Soil Texture
                                                                             (ft/sec)
                                           Sand or sandy loam                 2.5
The velocity of water flow must be
                                                Silt loam                     3.0
high enough to prevent siltation in
                                            Sandy clay loam                   3.5
the channel but low enough to
                                               Clay loam                      4.0
avoid erosion. Listed on the next
                                            Clay or silty clay                5.0
page are the maximum velocities
                                         Fine gravel, cobbles, or
for drainage areas of 640 acres or        graded loam to cobbles
                                                                              5.0

less. The velocity should be no        Graded mixture silt to cobbles         5.5
lower than 1.5 feet per second. A         Coarse gravel,shales,
lower velocity will cause siltation,           or hardpans
                                                                              6.0

which encourages moss and weed
growth and reduces the cross
section of the channel.
Hydraulic Gradeline
  Channel Velocity
The most widely used equation for designing outlet channels was
developed by Robert Manning in 1890 and is known as Manning's
equation:
                                   2   1
              1.49
           v      R s             3   2
                n
                         where
         V = average velocity of flow (ft/sec),
             n = coefficient of roughness,
                R = hydraulic radius (ft),
        s = slope of hydraulic gradient (ft/ft).
Manning Routine
      Design Process Flowchart
   Background
                                          Determine Drain
    Information           Select DC,
                                               Sizes
(Soils, Topo, Crops)       Spacing
                           & Depth

     Drainage
      Needed                              Installation
                       Develop System
NO
                           Layout

     Confirm
      Outlet           Determine Grades
NO                          & Depth
Drainage Coefficient
          4K
        c
        D 2( d )
            2 h
             h 2

          S




K                                               K
    h

                 S
                                           d
    Impermeable or Restricted-Flow Layer
 Drain Spacing & Depth

•Design for uniform depth throughout system
(depends on layout)

•Depth will of course vary on flat and rolling
topography
                       Depth-Spacing Relationships

                     120
Drain Spacing (ft)




                     100
                      80
                      60
                      40
                      20
                       0
                           2.5          3           3.5         4          4.5            5
                                                   Drain Depth (ft)
                                 3/8" Drainage Coefficient    1/2" Drainage Coefficient
                                 3/4" Drainage Coefficient
Drain Layout Comparison
Drain Layout Comparison
 Drainage Costs
Spacing (ft)   Costs ($/acre)
     10            3588
     20            1825
     30            1256
     40             972
     50             802
     60             688
     70             574
     80             517
     90             460
    100             452
             Increase Yield (bu/acre)
Spacing (ft)
                Corn        Soybean
    10          24.2          52.7
    20          24.2          52.7
    30          24.2          52.7
    40          24.2          52.7
    50          24.2          43.35
    60           22           33.15
    70           22           23.8
    80          17.6          14.45
    90          15.4          5.95
   100          13.2           3.4
Spacing (ft)   Rate of Return (%)
     10              4.87
     20              9.55
     30              13.37
     40              16.81
     50              17.16
     60              15.82
     70              14.63
     80              10.85
     90              6.66
    100              4.42
                                 Cost/Acre          
                                                 Crop Yield   Rate of Return
Cost or Yield Ratio (%)‫‏‬

                           100




                                                                               Profitability
                                             Tile Density
                                               Spacing
      Design Process Flowchart
   Background
                                          Determine Drain
    Information           Select DC,
                                               Sizes
(Soils, Topo, Crops)       Spacing
                           & Depth

     Drainage
      Needed                              Installation
                       Develop System
NO
                           Layout

     Confirm
      Outlet           Determine Grades
NO                          & Depth
System Layout
System Layout
System Layout
Contour
 Map
           System Layout
                                                        6 t
                                                         0
                                                       9. f.




                                                        4 t
                                                         5
                                                       9. f




                                                        3 t
                                                         0
                                                       9. f




                                                        1 t
                                                         5
                                                       9. f




                                                        0 t
                                                         0
                                                       9. f




pm do ot f nt l t n
 t z             a i
O i i e f rCsoI s lao   O i i e f rD i ae a rM ae et
                        pm do r ng We a gm
                         t z        a     t   n   n




          Cost Differential: $50/acre
      Design Process Flowchart
   Background
                                          Determine Drain
    Information           Select DC,
                                               Sizes
(Soils, Topo, Crops)       Spacing
                           & Depth

     Drainage
      Needed                              Installation
                       Develop System
NO
                           Layout

     Confirm
      Outlet           Determine Grades
NO                          & Depth
Drain Sizing Tool
Result
Display
Materials
Drainage Materials
Drainage Materials
Drainage
 Coeff.
Drainage Coefficient
Design
Criteria
Tile Mathematics

10 = 3 x 6
12/2 = 8
Sedimentation
  Options
Design
Chart
Can be
Saved
Lateral Specification
Lateral Specification
Inlets
Questions?

								
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