AutoCAD Civil 3D

[#1]

Hey

I have a big hole in the ground in my model.  Its easy to get the volume of cut with C3D.  But I have a topsoil layer, weathered rock layer and then solid rock, I basically need to break them down into different volumes.  The way I would normally do it is calculate the topsoil, then work out the weathered rock and minus the topsoil, then for solid rock cut I minus the topsoil+weathered rock.  Is there a better dynamic way of doing this?  I have attached the 3 volumes I need for info

[#2]

does each  layer have a constant datum?

[#3]

Have you tried volume surfaces egl vs total excn model, base topsoil vs total excn, base weathered vs total excn. You will still need to do a trivial calc to compute the topsoil and weathered volumes and the rock volume is direct from the model.

Not sure that this is any better than your current method though but you can produce pretty pictures.

you'd need to create models including the side slopes for each horizon to directly report volumes which is probably more hassle than it's worth.

[#4]

Thats where I was heading with one twist. If the datums are constants you can tweak the FG build elevation  and one volume surface could be used for the three quantities.

[#5]

Looks like a quarry or openpit mine

[#6]

Duh...

Run an alignment through it, sample lines , sections compute materials! ( no extra surfaces required)

Dang I hate when I only think vertically

[#7]

I'll give this method a try although when using it the sample line spacing will need to be tight to minimise errors inherent in a sectional method.

[#8]

If it is a quarry or open pit  then the sectionsmethod is suitable. True, it may generate some kind of minimum error, however the sections are generated automatically and give you the chance to give strictlytrack to the mining and monitors the floor levels.

I have compared the results of the calculated volumes between two triangulated surfaces using sections and other programs as Terramodel, Surpac, Surfer, etc.. The results are very similar.

[#9]

If the baseline for the sections is dragged and the sections run at 90 degrees to the original line this will give a good check on the volumes - only in a quarry/open pit situation, no good for roads etc