TIN-to-Channel Calculations
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on 23 August 2016 11:00 AM

TIN-to-Channel Calculations

The TIN-to-Channel calculation method computes several values relating the Input File (and the Additional File if one is present), and the Channel Plan file. It will only calculate where the two surfaces overlap.

        Cut Volume: Volume above the design template.

        Overdepth Volume: Volume above the overdepth level.

        Contour Volume: Reports overdepth material only in areas only where the depth is shoaler than the design template.

        Fill Below Depth: Volume of material that must be added to bring the surface up to the depth template.

        Fill Below Overdepth: Volume of material that must be added to bring the surface up to the overdepth level.

        Cut Area: Area of ‘Cut Volume’.

        Fill Area: Area of ‘Fill Below Depth’.

        Overdepth Area: Area of ‘Overdepth Volume’.

        Overdepth Fill Area: Area of ‘Fill Below Overdepth’.

The Report Options in the Volume Calculation dialog enable you to configure which values are included in your volumes report:

        Include Surface Areas: Reports areas corresponding to the cut and overdepth volumes, and the two fill volumes.

        Include Overdepth Volume: Reports all, Non-Contour overdepth volumes.

        Include Contour Overdepth Volume: Reports overdepth material only in areas only where the depth is shoaler than the design template.

        Include Fill Volume: Reports Fill Below Channel and OverDepth.

Additional options in the dialog affect the report display:

        Include Records with no Volume: By default, the program will omit any bordered areas where the bottom is less than the overdepth. If you would prefer to report all areas, check this option.

        The Itemize by selection determines how the volumes are tabulated:

        Channel Face


        Channel Zones (Only when you have defined zones for your channel file.)

        Border File (When you have one or more border files (*. BRD) loaded in the Borders tab.)

Standard TIN-to-Channel Volumes

For a straight comparison between your survey surface and the channel file. TIN MODEL requires only the channel file or a 3D planned line file with the Input data file in the initial setup dialog.

Note: If you want to see this comparison itemized by section, you must include a planned line file.

Building the TIN Model for Standard TIN-to-Channel Volumes

In the Volume Calculations Dialog:

Sample TIN-to-Channel Settings

1.       Select ‘TIN to Channel’.

2.       Set your report options.

3.       Click [Calculate].

Beware! Use caution when computing volumes where the survey lines are not perpendicular to your side slope. Because of the way TIN Models are created, your volumes may be overstated. We are working on ways to improve on this, but nothing will be perfect.

Beware! With so many different options that can affect your out­come It requires some careful checking to ensure you are classify­ing the material as either accumulated or depleted. Such options include:

        XYZ Files are in Depth or Elevation

        Initial File survey came before or after the Additional File survey

Sample TIN to CHN Report Itemized by Channel Face—Beginning (top) and End (bottom) Data at the break has been omitted.

Sample TIN to CHN Report Itemized by Section—Beginning (top) and End (bottom) Data at the break has been omitted.

Dual TIN-to-Channel Volumes

If you include an Additional File in your model, a Dual TIN tab appears with options for either of two reports:

        Channel Zones and Planned Lines

        Channel Faces and Border Files

Dual TIN to Channel Volume Options

Channel Zones and Planned Lines

The Channel Zones and Planned Lines report includes the volumes of material above the design grade and in the overdepth area for each TIN surface itemized by zone.

Sample Dual TIN to CHN with Zones and Planned Lines

Channel Faces and Border Files

This report calculates volumes for each TIN surface (where the Input file is labeled ‘Before’ and the Additional file is labeled ‘After’) and the difference for each border area. The report can include the volume above design grade, volume in overdepth, contour volume and area, according to the values selected in the Single TIN tab. The totals at the bottom total all of the before, after and difference values.

Sample Dual TIN to CHN with Borders

TIN-to-Channel Volumes with Multiple Channel Files

If you have multiple nested channel files (*.CHN), TIN MODEL can use the Philadelphia method to calculate the volume between each one.

The channels in the following figure show the situation for which this process was developed. They had previously dredged to the depths of the upper two channels, but needed to expand the channel design to that described by the deeper two channel profiles. Thus the channels represent the design depth and overdredge depth of the original channel and the new, larger channel.

Sample Nested Channel Profiles

Sample Channel Files


Maintenance Dredging:

CHN1: Above Design

CHN2: Overdredge



New Dredging Area:

CHN3: Above Design

CHN4: Overdredge

It reports the based on the areas defined by a center line file and a section file. For each section, the volumes are reported for the areas left and right of center.

Volumes Calculated Left and Right of Center for Each Section

To calculate volumes in this manner requires a specialized setup listing your channel files and the line files.

1.       Build your TIN model.

2.       Select VOLUMES-CALCULATE to access the Volumes Calculation dialog.

3.       Click [MultiChannel Philadelphia]. The Multi Channel dialog will appear.

Sample Multi Channel Philadelphia Dialog

4.       Enter your channel files (*.CHN) and your center line and section files (*.LNW) and click [OK].

As the program calculates the volumes, it draws each section to the screen:

        Material above CHN4 is yellow.

        Material above CHN3 is blue.

        Material above CHN2 is green.

        Material above CHN1 is red.

Sample Volumes in Process

The resulting volumes report shows the volumes for each section and the accumulated volumes as each section is completed.

TIN-to-Channel Volumes with a Zoned Channel

A TIN-to-channel comparison in the TIN MODEL program typically reports a volume for each face of your channel. In a complex channel, it might be more helpful for you to define the areas in your channel for which volumes will be calculated. That is exactly what we do with channel zones. Before you can calculate the TIN-to-CHN volume with zones, you will define your channel template (*.CHN) and your desired zones in ADVANCED CHANNEL DESIGN.


Note: Zoned calculations are not limited by border files.

Zoned TIN-to-Channel calculations require an input file and the zoned channel file.

Initial Data for Zoned TIN to Channel Calculations

In the Volume Calculations Dialog:

Sample TIN-to-Channel Settings

1.       Select ‘TIN to Channel’.

2.       Select the ‘Use Channel Zones’ option.

3.       Set your report options.

4.       Click [Calculate].

Sample Zoned Report

In the TIN MODEL interface, create a single CHN face (channel design surface) then calculate the amount of fill required to bring the TIN surface up to the design surface.

1.       Build your TIN model.

2.       Select CALCULATE-SCOUR FACE. The Scour Face dialog will appear with a map display of your TIN model.

Sample Scour Face Dialog Display

3.       Define the horizontal location of the top edge of the scour face surface.

        To use the cursor:

i.         Click the Digitize Top Edge icon.

i.         Click in the map display defining the top edge.

        To use a planned line file:

i.         In the LINE EDITOR, create an LNW file containing only one line that defines the top edge of the scour face.

i.         In the Scour Face dialog, click on the Import Top Edge icon. A File Open dialog will appear.

ii.       Select the a planned line file created in step 1 and click [Open].

The defined edge will appear in the map display.

Defining the Top Edge of the Scour Face

4.       Enter the scour face parameters:

        Z-value Bottom: Depth at the lower edge of the channel face.

        Z-value Top: Depth at the upper edge of the channel face.

        Width of Face: The horizontal distance from the top edge to the bottom edge of the face.

Note: The slope of the face is calculated using the Width of Face and the change in depth between the bottom and top of the face.

Scour Face Parameters.

Previewing the Scour Face CHN

5.       Generate the channel file.

a.       Tin_GenerateCHNIcon.pngClick on the Generate Channel icon. The channel face will be created according to your specifications and drawn on the Scour Face map display for you to preview.

b.       If you need to adjust the channel file, edit the scour face parameters and click the Generate Channel icon again.

c.       tin_ScourSaveCHNIcon.pngWhen you are satisfied with the channel preview, save it to CHN format. Click the Save Channel icon and name your file. The CHN file will be stored, by default, to your project folder.

6.       Calculate the scour face fill volume.

a.       tin_ScourVolCalcIcon.pngClick the Calculate Volume icon. The TIN MODEL Volumes Calculation dialog will appear. The settings will default to those for a TIN-to-CHN volume calculation using the channel file you just created.

b.       Verify the volume calculation options and click [Calculate]. The resulting volumes calculations are displayed in the dialog and stored to the tin_report_Date_Time.txt file in your project folder.

Resulting Scour Face Volume