What is cut and fillin construction?

A balanced site generates exactly enough suitable cut to supply its own fill needs after shrinkage, so nothing is imported or exported. Civil engineers often design toward balance because trucking dirt is expensive in both directions, but real sites rarely balance perfectly. The estimate should always show the net import or export in cubic yards, since that number, with the haul attached to it, frequently dominates the earthwork cost.

Because the soil changes density at every step. In the bank it sits at natural density; excavated, it swells (an illustrative 25 percent for common earth); compacted as fill to a spec like 95 percent Standard Proctor, it ends up denser than the bank, shrinking an illustrative 10 to 15 percent below the original bank volume. So 1 bank cy might place only 0.85 to 0.90 compacted cy, and the balance math has to account for it.

The grid method overlays the site with uniform cells, averages the cut or fill depth at each cell's corners, multiplies by the cell area, and sums cut cells and fill cells separately. The average end area method takes cross sections at intervals, averages the cut or fill area of adjacent sections, and multiplies by the distance between them. Both produce cubic yards you then adjust for shrink, swell, and topsoil stripping.