Select a design trial listed at the bottom of the Design/Analyze dialog, then select the Open button, or select the Create button to create a new design trial

3.7.6 Weir Component

When the Culvert Designer/Analyzer is in analysis mode, roadway overtopping can be considered in the analysis of an embankment cross-drain system. The overtopping component acts as a weir, and will automatically be added to the Culvert Component list at the bottom of the Culvert Designer/Analyzer.

Select one of the three methods for entering overtopping data:

x Not Considered x Broad Crested x Roadway

x Roadway (Constant Elevation)

The overtopping component is only available when the Culvert Designer/Analyzer is in Analysis mode.

Simply right-click any CulvertMaster table to access the new Copy-to-Clipboard feature. This allows you to place the table information on the Windows Clipboard to be used in other Windows applications.

Overtopping Not Considered

If the Overtopping Not Considered method is chosen, CulvertMaster will not take into account the discharge across the roadway when the headwater elevation exceeds the roadway elevation in the analysis of the embankment cross-drain system.

Broad Crested Weir

When the Broad Crested method is selected for the overtopping component of the embankment cross-drain system, CulvertMaster will analyze the roadway overtopping component as a broad crested weir, with the following data:

x Weir Coefficient – Typically in the range of 2.5 to 3.3 in English units and 1.37 to 1.82 in SI units.

x Length - The weir length. The weir length is measured perpendicular to the direction of flow.

x Crest Elevation - This is the elevation of the roadway. Discharge over the weir will begin when the computed headwater elevation is greater than the crest elevation.

x Discharge - The discharge associated with the design storm or check storm. This value can be changed in the Watershed tab of the Culvert Designer/Analyzer dialog. It is non-editable in this window.

x Headwater Elevation - The computed headwater elevation.

Roadway

When the Roadway option is selected for the overtopping component of the embankment cross-drain system, CulvertMaster will analyze the roadway overtopping component using the methodology outlined in HDS-5.

Use the table to enter points that describe the profile of the roadway:

x Station - The stationing along the roadway centerline.

x Elevation - The elevation corresponding to the station.

Additional data:

x Roadway Type - Select either paved or gravel. The calculation of the overtopping coefficient is dependent upon the roadway type. The Paved option models the roadway as having a paved surface, and the Gravel option models the roadway as having a gravel surface.

x Roadway Width - The distance across the roadway parallel to the direction of flow. This value is used to compute the overtopping coefficient.

40 Chapter 3 – Project Settings x Discharge - The discharge being conveyed by the roadway component of the

embankment cross-drain system.

x Overtopping Coefficient - The coefficient used in the weir equation for calculating the discharge over the roadway. It is a calculated value, and is non-editable.

x Headwater Elevation - The computed headwater elevation for the embankment cross-drain system. It is non-editable.

To insert or delete a row from the table, use the Insert and Delete buttons. Setting the values to zero may cause errors in the calculations.

Roadway (Constant Elevation)

When the Roadway (Constant Elevation) overtopping option method is selected for the overtopping component of the embankment cross-drain system, CulvertMaster will analyze the roadway overtopping component using the methodology outlined in the HDS-5 manual.

Because the roadway elevation is constant, the defined crest elevation value is applied across the enitre length of the roadway.

Roadway Type:

Select either paved or gravel. The calculation of the overtopping coefficient is dependent upon the roadway type.

Paved

Model the roadway as having a paved surface.

Gravel

Model the roadway as having a gravel surface.

Roadway (Constant Elevation):

Length

The roadway cross section length. The roadway length is measured perpendicular to the direction of flow.

Crest Elevation

Thecrest elevation. This is the elevation of the roadway. Discharge over the weir will begin when the computed headwater elevation is greater than the crest elevation.

Roadway Width

Enter the width of the roadway. This is the distance across the roadway parallel to the direction of flow in the analysis. This value is used to compute the overtopping coefficient.

Discharge

This is the discharge being conveyed by the roadway component of the embankment cross drain system. It is a calculated value, and is non-editable.

Overtopping Coefficient

This is the coefficient used in the weir equation for calculating the discharge over the roadway. It is a calculated value, and is non-editable.

Headwater Elevation

The computed headwater elevation.

Discharge Coefficient

The Discharge Coefficient used in the roadway overtopping equation outlined in the HEC-22 methodology. It is a calculated value, and is non-editable.

Submergence Factor

The Submergence Factor used in the roadway overtopping equation outlined in the HEC-22 methodology. It is a calculated value, and is non-editable.

3.7.7 Culvert Component

Properties entered in this dialog are used with the location properties to model a single culvert component of an embankment cross-drain system.

Enter known data for each group:

x Section x Inlet x Inverts

Use the Inverts/Solve For control to immediately calculate the unknown property for the Inverts group from other known properties.

You can use the Design/Analyze dialog to copy a design trial for use as a culvert component.

To open an existing culvert component or create a new culvert component: