Cut and fill between existing ground and a design surface, from survey points. Composite TIN, a grid check and a cartogram of squares side by side, with an Excel report and a DXF for CAD.
Sample data. Commercial site 300 × 220 ft: 667 survey points, building pad and parking with 3:1 slopes to daylight, limit of work at the daylight line, 0.5 ft topsoil strip, 15 % fill shrinkage. Replace it with your own files.
At each node, top to bottom: design level, existing level, depth of cut (C) or fill (F). In each square: cut and fill volume. Sums by row on the left, by column at the bottom. Italic volumes are partial squares.
Real coordinates, so it lands on your drawing. Layers for the grid, levels, depths, volumes, the zero line and the tables. Open it in AutoCAD or Civil 3D and save as DWG.
The Excel file has the inputs, both methods, the balance with live formulas, and depth at every point.
Main method, composite TIN. Both point sets are joined into one triangulated surface. At every vertex the page reads the existing level and the design level by linear interpolation in each original surface. Each triangle is a prism between the two surfaces. Where a triangle crosses from cut to fill, it is split exactly at the zero line, so cut and fill are not netted inside one triangle.
Check, grid method. Both surfaces are sampled at the centre of square cells and the depth is multiplied by the cell area. The two results are independent enough to catch a bad file, a wrong column order or a design that does not cover the area. A difference under 2 % is normal.
Cartogram, square method. The cartogram of earthworks as it is drawn in Civil 3D or by hand. Squares sit on whole coordinates (for 5 ft squares: 5020, 5025, 5030 …). At every node the page reads both levels, and the working depth is their difference. A square with one sign holds a²·Σh/4. A square crossed by the zero line holds a²·(Σh+)²/(4·Σ|h|) of cut, and the same with the minus depths of fill. Squares cut by the limit of work are measured by sampling both surfaces at 100 points inside it. Untick the box to count whole squares whose centre is inside, as on a paper cartogram. Smaller squares follow the ground better: from about 10 ft (3 m) up, volume is lost across slope breaks.
Balance. Topsoil strip comes off the cut and is added to the fill, because stripped soil is stockpiled, not used as fill. Fill is divided by (1 − shrinkage) to give the bank volume needed. Net = cut after strip − fill bank: positive is surplus to export, negative is material to import.
Limits of this version.
Built by Sergei Grishutov, quantity surveyor and former head of a construction survey department. grishutov.github.io