Cut and fill between DTMs

You can use this function to calculate the cut and fill volumes between two DTMs. One of the main uses of the DTM CUT AND FILL VOLUMES function is to help with road design.

= fill

= cut

= boundary string

Note: The DTMs you use must be created on the same plane.

To run this function: Choose Surfaces > Volumes > Cut and fill between DTMs, or...

In the Function Chooser, type DTM CUT AND FILL VOLUMES, and press ENTER.

Fields on the DTM cut and fill volumes form

Field	Description
Define the first DTM
Location	The name and location of the first DTM.
[Refresh]	Loads the Object ID and Trisolation ID drop-down lists with the objects and trisolations of the DTM. In Surpac 6.6.1 and earlier versions, when you selected a DTM in the Location field, Surpac would load the DTM, validate it, and then load the Object ID and Trisolation ID drop-down lists. You could not interact with the form until the process was complete, which could be a long time for some large DTMs. Now, Surpac does not load the drop-down lists until you click the Refresh button, and validation does not occur until you click Apply in the form. Any validation errors are reported in the Message window.
Object ID	The object number of the first DTM. You can type the Object ID or select it from the drop-down list, if the list is loaded.
Trisolation ID	The trisolation number of the first DTM.
Define the second DTM
Location	The name and location of the second DTM.
[Refresh]	Loads the Object ID and Trisolation ID drop-down lists with the objects and trisolations of the DTM.
Object ID	The object number of the second DTM. You can type the Object ID or select it from the drop-down list, if the list is loaded.
Trisolation ID	The trisolation number of the second DTM.
Define the volume boundary string
Location	The name and location of the boundary string file.
Boundary string	The string number for the boundary string.
Define the file for the cut and fill boundary
Location	The name and location of the string file to save the results.
ID number	The identification number for the string file to save the results.
Fill string	The number for the fill string.
Cut string	The number for the cut string.
Boundary string	The number for the boundary string.
Define reporting options
Decimals	The number of decimal places used in the areas and volumes in the report.
Density	The density value used to calculate the Nett tonnage of the Nett volume.
Report format	The file format for the report. Options are: .not, .csv, .htm, .html, .rtf, .pdf, and .ps.
Detailed report	Selected: Additional information, such as the DTM extents and areas of elevation, are included in the report. Cleared: No additional information is included in the report.
Report by elevation	Selected: The report specifies the cut and fill volumes for the elevation intervals identified in the Range field. Cleared: The report does not specify the cut and fill volumes by elevation.
Range	The elevation intervals to use if Report by elevation is selected.

Output

This function reports:

the cut volume and the surface area where cut occurs.

Cut volume is the volume, within a boundary string, between the second DTM and the first DTM where the second DTM is lower in elevation than the first DTM.

the fill volume and the surface area where fill occurs

Fill volume is the volume, within a boundary string, between the second DTM and the first DTM where the second DTM is higher in elevation than the first DTM.

Nett volume, which is Fill volume minus Cut volume.
the area where no cut or fill occurs (known as the common area)
the volumes and areas for each boundary segment
the total tonnage

You can also report this information by elevation by selecting Report by Elevation. If you report by elevation,the description fields contain the grand total values, not the totals of the elevation range reported.

The results are saved as three strings in a string file; the boundary string, the cut string and the fill string. The volumes and areas reported are stored in the description fields of the first point of the boundary string:

Field	Contains
D1	Cut volume inside the boundary segment
D2	Cut area inside the boundary segment
D3	Fill volume inside the boundary segment
D4	Fill area inside the boundary segment
D5	Area of triangles common to both DTMs inside the boundary segment
D6	The total tonnage of material, calculated by subtracting the cut volume from the fill volume

When calculating the volume between two surfaces created on a non-horizontal plane, the process is:

The surfaces and boundary string are transformed so that the surface plane is horizontal (at an elevation of 0).
The volume calculation process proceeds as for a horizontal plane surface.

Sample Report

Example Cut and Fill report

Troubleshooting

DTMs created prior and post Surpac 6.2

Message	Description
`String xxxx not found`	The boundary string specified does not exist in the boundary string file.
`String xxxx segment xxxx is open. It must be closed to continue.`	The specified segment of the boundary string is not closed. There may be other segments in the boundary string that are open but they are not reported. View the boundary string in the Graphics module and fix the problem before proceeding.
`Object 1 Trisolation 1 does not exist.`	All triangulated objects in DTM files are identified by an Object number and Trisolation number. The Create DTM function always identifies the Object as Object 1, Trisolation 1. It is possible to changes these identifiers by editing in the Graphics module. This is probably the reason why the Object cannot be found. If in doubt, recreate the DTM with the Create DTM function.
`The DTM boundary string is missing - Cannot continue without the boundary`	An integral feature of a DTM is a boundary string, which represents the extent of the DTM triangles. This boundary is missing. The most likely cause is that a text editor was used to edit the DTM file. Recreate the DTM using the Create DTM function.
`Boundary point is outside DTM Y=yyyyyy.yyy, X=xxxxxx.xxx`	A point at the coordinates specified is outside the boundary of the DTM. It is not possible to calculate cut and fill volumes with this point outside the DTM boundary. Adjust the boundary string and try again.
`No triangles remaining for volume after clipping with boundary string.`	After clipping the second DTM with a segment of the boundary string there are no triangles left to calculate a volume. This is an unexpected situation and you should contact the nearest GEOVIA Support centre and report the problem.
`The selected DTMs were not created on the same plane.`	The DTMs used must be created on the same plane. Choose different DTMs, recreate the DTMs on the same plane, or transform the data in one of the DTMs to match the plane of the other.