Culverts

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Culverts
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Culvert Types in HEC-RAS
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Cross Section Locations
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Typical Culvert Profile
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Culvert Flow Types
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Culverts Inlets and Outlets
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Culvert Inlets and Outlets
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Culvert Inlets and Outlets
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Culvert ModelingExpansion and Contraction
Coefficients at the 4 cross-sections for a
culvert (example)
Expansion Contraction Cross-Section 4
(furthest US) 0.5 0.3 Cross-Section 3
0.5 0.3 Cross-Section 2
0.5 0.3 Cross-Section 1(furthest DS)
0.3 0.1
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Ineffective Flow Areas
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Adding the Culvert(s)
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Input Requirements for Culverts

• Culvert ID
• Solution criteria (inlet, outlet, or highest
  energy grade line)
• Shape (circular, box, arch, etc.)
• Dimensions (diameter, width, etc)
• FHWA chart (pages 6-25,26 of hydraulic
  reference manual)
• FHWA scale (same table as chart )
• Distance to upstream cross section

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Input Requirements for Culverts(Continued)

• Length
• Entrance loss coefficient (tables 6.3 and 6.4 of
  hydraulic reference manual)
• Exit loss coefficient (0.3 to 1)
• Mannings n value (tables 6.1 and 6.2 of
  hydraulic reference manual)
• U. S. And D.S. invert elevations
• Centerline stations in relation to U. S. And D.
  S. cross sections

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Input Requirements for CulvertsRoadway Data

• Roadway width
• Distance to U.S. Cross section
• Weir coefficient
• Station - elevation points

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Adding the Culvert(s)
Select the Brdg/Culv button from the geometry
data window
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Adding the Culvert(s)
This brings up the Bridge Culvert Data window
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Adding the Culvert(s)
From the options menu, select Add a Bridge
and/or Culvert
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Adding the Culvert(s)
This brings up a window asking for the river
station of the bridge. It will locate the bridge
numerically between cross-sections
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Adding the Culvert(s)
This brings up a window with the adjacent
upstream and downstream cross-sections plotted
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Adding the Culvert(s)
Next, select the Deck/Roadway button from the
Bridge data window
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Adding the Culvert(s)
Notice the weir coefficient and max submergence
window are showing the default values
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Cross Section Locations
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Adding the Culvert(s)
Enter the data for the required values. Note
that the U.S. and D.S. sideslopes are for
cosmetic purposes only unless using the WSPRO
method for low flow. Also note the zeroes for
the low chord
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Adding the Culvert(s)
After selecting OK from the bridge deck window,
it replots the U.S. and D.S. x-sections showing
the filled in road section
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Adding the Culvert(s)
After selecting OK from the bridge deck window,
it replots the U.S. and D.S. x-sections showing
the filled in road section
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Adding the Culvert(s)
To enter the culvert data, first select the
Culvert button
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Adding the Culvert(s)
This brings up the Culvert Data Editor window
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Adding the Culvert(s)
Enter the data and select OK ...
Table 6.3 or 6.4, HRM
Table 6.1 or 6.2, HRM
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Adding the Culvert(s)
The plot is then updated to show the culvert
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The End