grading-volume calcs

Hello,

I do not do these kind of calculation often but I have to. I am wondering what program I should use. I have some survey points of an area of land. I need to do some calculations of excavation to remove land to a particular elevation. I am very knowledgeable with revit, solidworks and autocad. I really dont like autocad 3d capabilities however. We only have regular autocad 2010 at work. With solidworks I was thinking I would draw 3d lines in different planes and extrude. I could probably do that in autocad too. Is that the best way to find these type volumes you think without using autocad 3d civil which ive never used. We do not need exact figures. Basically, an idea of what we are dealing with. Any insight would be great.

Tnx

If it only needs to be rough then I would just do it on pen and paper. Break the overall area down into smaller areas and then approximate the volume for that small area using simple shapes (e.g. a rectangle). Then sum those volumes together to get the total volume.

Yea I have done that in the past. There is something called triangulation or something. You just use a bunch of triangles and find the area X distance for the volume of excavation. However, I would like to figure out something along the lines of entering a bunch of x,y,z (survey elev.) points and work with that. It is a good thing to know in any construction related industry. I will ask around.

To compute the grading volume change you need to create two surfaces, one that defines the surface before excavation and the other for after. For civil engineering applications a TIN (Triangulated Irregular Network) is used to define the surfaces. The TIN is simple a 3D array of triangles. Civil 3D has features for creating TINs from an array of 3D survey points or from contour lines. Google Earth uses TINS but they are fairly crude. Civil 3D 2012 had a feature for easily capturing TINs from Google Earth but the feature was removed in later versions.

If you do not have access to Civil 3D you could create the triangles as 3DFACES or 3D polylines. The volume under a 3D triangle is simply the product of the average height of the three corner and the area of the projected triangle onto a reference plane. Perhaps someone has already written and VLISP program for this.

yea. i will just do the best I can by hand until I do some more research. There are lots of programs out there. We do not do this often we are steel fabricators.

I should have mentioned that Revit supports cut and fill analysis since your profile includes Revit. You can import the points to Revit and then use the Massing & Site features to build a surface and then use the Graded Region feature to compute volumes.

yes that works. tnx. i do not use revit for this one company. they only use autocad and tekla. i do not use my computer there at all. i dont think i am even allowed.