MAGNET Field: Calculating a surface volume

This guide is about creating a new stockpile surface from scratch in MAGNET Field with Survey > Surface.

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MAGNET Field: Calculating a surface volume

You can navigate to Survey > Surface to create a TIN or mesh surface of a desired area that can be used to compute earthwork volumes, be exported to machine control formats for precise excavation and grading, or for further CAD design.

From the main MAGNET home screen, press the Survey menu button.

Press the Surface button.

This guide is about creating a new stockpile surface from scratch.

Select New from the first drop-down menu, and tap in the white box to add a name.

Ensure that Boundary is selected.

This will ensure that the resulting volume is calculated from the points that define the outermost extents of the created surface.

Press Next.

MAGNET Field has further volume calculation options depending on your requirements.

Select Append To if you wish to add more data to an existing surface.

Min Elev: The volume is calculated from a plane created at the point of minimum elevation of the surface.

Max Elev: The volume is calculated to a plane created at the point of maximum elevation of the surface.

Fixed Elev: The volume is calculated from the surface to a flat plane created at a desired elevation. Manually enter the elevation, or use the Map or List buttons to select an elevation from a point already in the job.

Plane: The calculation is performed from the surface to a flat plane created from three known points. These can be entered manually or chosen from the Map or List buttons.

Design Surface: This will calculate the volume difference between the surveyed surface and another defined surface, e.g., a created design. Manually enter the name of the second surface, or select it using the List button.

No Volume Calc: Use this to create a surface but not calculate a volume. The volume calculation can be done after data collection at any point.

Feature code settings

It is a best practice to use feature codes when surveying a surface.

Using line strings to define the lower and upper boundaries of the surface and a point code for spot heights allows for clear visualization and easy identification if you wish to create a surface or calculate a volume at a later time.

Ensure the code selected is denoted as Use in Surface, and if a line feature, Breakline.

If unsure, this setting can be found under the Edit > Codes menu.

Highlight a code from the list, and press Edit.

Survey surface

Begin recording the desired outermost boundary of the surface.

This example is using the Bottom of Bank (BB) code and string number 1.

Once a third point has been surveyed, the triangular mesh begins to be created.

Change the code and string number to record the top of the feature.

This example uses Top of Bank (TB) and string number 1.

In both cases, don’t forget to select Close from the Control Codes list prior to recording the last point.

More surface detail can be added by using a point feature code, e.g., Spot Level. Once the surface has been fully surveyed, press the back arrow or home icon.

A cut/fill volume report will then automatically be generated for the surface just surveyed.

Press the folder icon to send this information to a *.TXT file for future reference.

Checking the created surface

To access the newly created surface, head to the Edit > Surfaces menu.

Highlight the relevant surface from the list.

Press Edit to change the properties of the surface.

Under the Style tab, you can change the surface Name, Layer, and mesh Color if desired.

Viewing the created surface

The surface can be viewed in the Map screen.

Press the map properties icon. 

Check the relevant DTM from the Surfaces tab.

The surface mesh along with associated points and linework will now be visible.

The surface can also be visualized in 3D.

Under the 3D tab, select desired Surface Fill options, and press the green check mark.

Back in the Map screen, select the 3D button. 

The DTM can now be rotated and panned using the second set of the icons on the right.