How to quantify excavation for remedial grading

Use the Removals tool to measure how much dirt must be excavated to grade an area down to a target elevation or depth, and download the daylight line for staking.

Written by Raymond Fuorry
Updated over a week ago

What the Removals tool does

The Removals tool quantifies excavation for remedial grading — for example, removing unsuitable material or grading an area down to a target. You outline the grading area on the scan, choose a target elevation or a fixed depth, and the tool returns the volumes to excavate plus the daylight line (the line on the existing ground where your excavation slope meets the surface) for your rover.

Availability: the Removals tool works on all scan tiers.

How to outline the grading area

To outline a removal area in TraceAir:

1. Select Plan & Track in the top left of the screen, then select Removals.
2. Click the starting point of the grading area, then continue clicking to trace its outline.
3. When you reach the endpoint, click the checkmark.

How to set the target: elevation or depth

After the outline, choose how the bottom of the removal is defined — this is the key decision in the tool:

• Grade to a specific elevation — the whole area is cut down to one target elevation (a "fixed bottom").
• Grade to a fixed depth — the cut follows the existing ground down by a constant depth everywhere.

Then:

1. Select the slope your equipment will run on the sides. A slope of 0:1 creates a vertical wall.
2. Enter the elevation or the depth, depending on the mode you chose.
3. Click "Get Quantities and Daylight Line."

How to read the quantities

The Removals tool reports the excavation in two parts, and their sum is your total dig:

• Contract Cut — the volume from the scan surface down to the Design surface.

• Sub-excavation Volume — the volume from the Design surface down to the bottom elevation or depth you specified.

• Contract Cut + Sub-excavation = the total dirt quantity to be excavated.

Note: in the map view, the blue line shows the bottom of the removal you're targeting, and the green line shows the daylight line — the line you start grading down from to reach that bottom.

How to download the daylight line for staking

To stake the removal in the field, click "Download CSV" in the results window. The file contains the coordinates of the daylight line, ready to load into your rover.

How to adjust the removal after calculating

Removal parameters can be changed at any point. Click Recalculate, enter a new slope or depth, and the quantities and daylight line update. Close the window with the X at the top.

Frequently asked questions

When do I use "fixed elevation" versus "fixed depth"?

Use a fixed elevation when you're grading the whole area to one target — a building pad or a road subgrade. Use a fixed depth when you're removing a consistent layer — for example, stripping a set thickness of unsuitable material that follows the existing ground.

What's the difference between the blue line and the green line?

The blue line is the bottom of the removal — the surface you're grading down to. The green line is the daylight line on the existing ground — where the excavation slope meets the current surface, which is where your crew starts the cut.

Does Removals work on a Basic (Silver) scan?

Yes, the Removals tool is available on all scan tiers, starting at Basic (Silver). The tool uses the scan surface and approximates the removal the same way on every tier.