Earthwork volumes

As soon as a pad or a corridor grades without problems, CivilCraft compares the proposed surface with the existing ground and reports cut and fill. The numbers update with every change.

Where to read them

• Earthwork in the right panel with nothing selected (the Project view), when there is at least one pad or one corridor.
• Earthwork in the right panel when a pad is selected (the same totals for the whole project).
• The line under a corridor's settings, with that corridor's own cut and fill.

The Earthwork block shows:

• Cut, Fill and Net (with "fill" or "cut" after it, whichever is larger)
• a line per item when there is more than one, for example "Pad 1: cut 120.4 cu yd, fill 310.2 cu yd"
• the method line: "Grid method: existing ground and the graded surface sampled every 0.5 ft inside the daylight lines (92,891 cells). No swell or shrink applied."

Volumes are in cubic yards in a feet project and cubic metres in a metre project.

How they are worked out

CivilCraft uses the grid method:

1. A grid of square cells is laid over the area inside every daylight line.
2. At the center of each cell, both surfaces are sampled.
3. Each cell counts as a prism: the difference in elevation times the cell's area. Where the proposed surface is lower, it is cut; higher, it is fill.
4. The cells are added up.

The cell size is chosen for you so that the rectangle around the graded areas holds about 250,000 cells, rounded to a tidy value (1, 2 or 5 times a power of ten). You cannot set it yourself yet. The method line tells you the size and the number of cells. Smaller cells are more accurate along the edges; on whole cells between flat planes the result is exact.

Things to know

• Only the area inside daylight lines is counted. Ground outside them is unchanged.
• A pad or corridor with a problem is not graded in and adds nothing. If the block says "No volumes yet: a pad needs to grade without problems.", look for a red box above it.
• Where items overlap, the later one has replaced the earlier inside its daylight line, and the overlap is counted once.
• No swell or shrink factor is applied. Multiply the results yourself if you need bank, loose or compacted volumes.
• Topsoil stripping, pavement and subgrade depths, and TIN-to-TIN prism volumes are not available yet.

Checking a result

• Turn Proposed (graded) on under Display and look at the contours inside the daylight lines.
• Move the pointer over the graded area: the status bar shows Ground and Graded. The difference is the cut or fill depth at that spot.
• For a corridor, the profile view's readout shows cut or fill on the centerline at every station.