Cut and fill

1. Make sure you have two surfaces created for comparison; i.e. an existing surface and proposed surface in C3D.
2. Next, create a new volume surface. There two methods for volume surface which are TIN volume or GRID volume. Choose either one and select your surfaces appropriately as shown in the diagram below:

3. Notice that when you hover your cursor (crosshair) over your Volume Surface, it will give you a +ve or –ve values depending on whether the area yield cut or fill as shown.

4. Once you have your Volume Surface created, you can begin to generate the Cut and Fill shade. In order to do that, you’ll need to go to the surface properties and choose the Elevation Banding (2D) (provided if you’ve created your drawing via the _Autodesk Civil 3D (Metric) NCS Classic template). Buzz me if you need illumination.

5. Subsequently, go to the Analysis tab. Choose only 2 ranges and click on run analysis. Change the Maximum Elevation values for ID no. 1 to 0 and the Minimum Elevation values for ID no. 2 to 0. 6. Click ok and you’re done. You might observe that at times your surface doesn’t mirror the surface you have in mind. Don’t fret, make use of the edit features under the surface properties i.e.; you can add Boundaries to show only the extent if your working area, cut/fill only…etc.

7. Last but not least, I have some engineers who came to me and ask whether C3D can generate the Cut and Fill shade in hatch pattern instead of hatch solid. Well the there is a workaround. The good thing with C3D is it comes together with AutoCAD and therefore it has the best of both worlds. What you need to do is to export the completed drawing to AutoCAD (File>Export>Export to AutoCAD)

8. Open your drawing using Civil3D as AutoCAD and you’ll notice that the solid hatch representing the cut and fill is not in 1 piece. This is the tedious part. You’ll need then to edit the hatch solid to another hatch pattern of your choice and inherit the properties using Match Properties. It’s not that hard after all…

Happy trying.


Tác giả : Wendy Lim Petaling Jaya, Selangor, Malaysia

"Civil 3D Nuts and Bolts: Volume Calculations and Making a Volume Exhibit"

Civil 3D 2006 and 2007 have a few ways you can do volume calculations. They include (but may not be limited to): Volumes from Corridor Sections, "Quick" Volumes, and building a Volume Surface.

Today we will talk about Quick Volumes and Volume Surfaces, including a way to make an exhibit that highlights your areas of Cut/Fill.

Remember, any image can be enlarged by clicking on it.

Start with your existing surface and proposed surface (or any two surfaces you need to compare). Your surface can be from grading objects, corridors, your own points, pasted surfaces, whatever it takes. Remember that if you built your corridor surface from the "TOP" codes, that your results won't just be earth volumes, but also stone and asphalt, etc. You can eliminate that problem by building another corridor surface from "DATUM" or "SUBGRADE"

For the Quick Volume go under the Civil 3D Surfaces Menu and Choose Utilities>Volumes

Make a volume entry, then choose the two surfaces that you would like to compare. BANG, done. If you change either surface (ie move a proposed ground profile so that your corridor updates) these numbers can be refreshed right away. This method is great for iterations.

Once you have come up with your optimized design, perhaps you want to make a volume surface. Picture your two surfaces as plates and fill in their differences with playdough. when you remove the plates, the playdough stays behind making a volume surface. Volume surface elevations and therefore contours, etc. are the difference between the two surfaces that made it. For example if you had a flat surface at elevation 10, and a flat surface at elevation 85, when you queried the elevations of the resulting volume surface, its elevation would be listed as 75.

To make a volume surface, Civil 3D Surfaces Menu>Create Surface. Choose TIN or Grid, then the style, and which surfaces you want to compare/contrast.

Now CRUNCH this volume surface and apply an elevation banding style of your preference so that you can show this to your client- where her trouble areas are for cut and fill.

Tác giả : Dana Breig Probert-an author of Mastering AutoCAD Civil 3D 2008.