# Cut and fill - can I find out where the areas are that have been cut?

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I have created an existing and proposed terrain and obtained figures for the cut and fill. Is there then a way of finding out where the cut and fill areas are? Thanks

Edited by Gilly

Cut&Fill are differential calculus approximations are based on the integral of the existing and proposed areas at each XYZ intersection

using wave frequency amplitude averaging variables based on the declared contour spacing.

In other words, the procedure builds a hypothetical 'best-fit' volume which it can query for parametric positive 'fill' and negative 'cut' values.

Therefore, there are no "cut and fill areas" per se, only relative computational volumes based on the integral.

However, 2d sectional slices of the existing & proposed DTM can be compared by polygonal area procedures

easily accessible via the worksheet. But this method will by necessity ignore the contour spacing depth parameter which can be approximated

via a generalized coefficient of sectional slope expansion between the slices

in order to calculate the 'if -then' +/- volumetric.

Oh my goodness! Are you saying that I can't automatically generate a plan showing where the cut and fill areas are but I can compare existing and proposed sections across the terrain? I have to give an answer by Wednesday so any help would be appreciated. PS. Thanks for your help on this.

Are you saying that I can't automatically generate a plan showing where the cut and fill areas are but I can compare existing and proposed sections across the terrain

There are surfaces and then there are volumes ( a volume has @ min. 4 surfaces ). The plan surfaces are areas easily described by graphic patterns, & hatches which define the 2d perimeters of the work. The height or depth is indicated by the plan contours which vary with the terrain.

But within the plan surface is the volume of the cut or fill which can't be shown graphically in planview except with contour lines, but can be indicated by comparison via sections cut across the existing and proposed plan areas.

Therefore, the correct protocol is to create a plan with X-Y grid section lines of the existing and the proposed or a composite of the two .

Then, a section sheet showing each of the X & Y grid sections via 2d cuts with elevation lines across the DTM 3d volume of the site. This reduces the 3d volume to equally spaced 2d profiles which can then be used to extrapolate the amount of cut / fill per each section. The closer the sections are to the unit of measure the more precise the final cut & fill calculations will be.

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