January 2012

So, in class last week, I had some folks that work in the mining industry and they needed to create a filling curve. What’s a filling curve you ask? Well, you know what the final grade is going to be but, how much volume material have you placed in this area once it reaches a specific elevation, well, that’s a filling curve.

I was racking my brain on how to do this. An elevation analysis didn’t work on the volume surface because that gave me the depth of fill, not the elevation of fill. With the new Volumes Dashboard Extension available through the subscription website, I came up with a solution. Now, this won’t actually plot a curve for you but it will compute the volumes at any elevation for you.

To start off with, you need two surface, 1) the existing ground and 2) the filled in surface (in this example, I’ll refer to them as EG and Fill Stack). In order for this to work, the existing ground must be trimmed out to the exact limits of the proposed ground so extract the border from the proposed ground and use it as a boundary in the existing ground (I would recommend creating a new surface, pasting the original EG into it and applying the boundary to that rather then modifying the original EG).

Just so you can see what is going on, here is a cross section across  the site.

EG and Filling Surfaces

As you can see, the existing ground varies quite a bit so it’s important to take that into consideration. What we need to do now is create a flat surface that represents the elevation that we have filled. Simple, create a rectangle, assign it the elevation you want, and add it to a knew surface (I’ll refer to this one as the Level surface). Now we can see this new surface in our cross section.

EG, Filling and Level Surfaces

The desired volume at this particular station is between three surfaces, the EG, the Fill Stack, and the Level surfaces. The volume we require is shown below but I can’t get that from comparing only two surface, I need to compare all three surfaces.

Required Volumes

I can calculate the fill between the Level surface and the Fill Stack surface

Fill Area comparing Level Surface to Fill Stack

And I can calculate the cut between the EG surface and the Level surface

Cut Area comparing EG Surface to Level Surface

You might have noticed that the required volume we need is the green fill area subtracted from the red cut area, and this is where the magic begins. Launch the Volumes Dashboard (it’s an extension if you are still using 2012 and, if history repeats itself, it’ll probably be incorporated into 2013 or whatever the next release will be) and create the two volumes surfaces that will result in the above cut and fill. The first Volume Surface I’ll create will have a base surface as the Fill Stack surface and the comparison surface of the Level surface (this one will be called Fill to Level) and the second Volume Surface I’ll create will have a base surface as the Level surface and the comparison surface of the EG surface (This one I’ll call Level to EG).

Volume Surfaces in the Dashboard

Unfortunately, right now, the numbers you are seeing aren’t correct. The reason for this is because the volumes surfaces are still taking into account the volume above the Level surface, I only want it to take into account the volume below the Level surface.

Volume Error

Well, the volume dashboard allows you to apply different cut and fill factors so, to prevent the volumes above the level surface from being used, simply set the cut or fill factor for that portion to zero.

Cut and Fill Factors Applied

Now simply move your Level surface up and down (grab the polyline and use the move command). If everything is set to “Rebuild Automatic” you’ll see these number automatically update. Now, there is no way that I’m aware of to take these number and have them automatically create a curve but you can have excel open on your other monitor and simply move the Level surface and type in the volume into Excel, repeat until you are done.

Now, you wouldn’t be keeping your license or job for long if you didn’t do some double checking so, how can you make sure the numbers you are seeing are correct? Well, create a new volume surface that compares the EG and the Fill Stack so you know what the total volume is and then move your Level surface above the highest elevation of your Fill Stack (the numbers should be the same) and then move your Level surface below the lowest elevation of your EG surface (the volume should be zero).

Maximum Fill Check

No Fill Check

One thing to make sure you do is to uncheck the volume surface you are using as the check so it’s not included in the totals on the left of the dashboard.

Hopefully you’ll start to see the value of using the volumes dashboard and some of the things you can do with it. The more I use it, the more I like it. If you come up with any other great ideas on how to use it, let me know and if they are awesome enough, I just might write a post about it and give you credit for it.

For more information on the Volumes Dashboard Extension, you can read about it HERE.


This has been a pet peeve of mine for a long time, survey figures don’t honor linetype gen. What does that mean? Basically, it means the linetype will not pass through vertices. If you have a survey figure with a lot of closely spaced vertices, it looks like a continous line even if you have a linetype assigned to it.

Survey Figure with Linetype Issue

That’s not what I want. What I want is something like this:

Text placed on figure to simulate linetype

Unfortunately, what I’m about to show you doesn’t work real well for generic linetypes (dashes, dots, etc.) but it works really well for putting text labels on your survey figure. The trick is to create a marker style that displays a piece of text. The text must be a block (you can enable background mask in the text if you want to, I did) and then assign that block to a new marker style. If you aren’t sure how to create a block in AutoCAD, click HERE.

The marker styles are found in the Settings tab of the Toolspace under General->Multipurpose Styles->Marker Styles. Create the style and use the block with the text in it.

Marker Style

Now that you have the marker style created, assign this to the survey figure style. Survey figure styles allow the use of quite a few markers, you can place them at the end, the beginning, and the vertices, as well as additional markers, and these additional markers is what we will be using to simulate a linetype with text in it. Edit your survey figure style and on the display tab, turn on the display of the Additional Markers.

Survey Figure Style - Displaying Additional Markers

Now that the additional markers are displayed, you need to choose the style and options for those markers and this is found on the Plan and Model tab of the survey figure style. Here you can specify the different marker styles for all the places markers can be used, down near the bottom is the Additional Markers section. Choose an appropriate marker style (most likely the one you just created) and then change the “Additional marker placement method” to At Interval. Choose an appropriate interval and you are done.

Additional Marker Settings

There are a few limitations to this technique

  1. The text can (and most likely will) be displayed upside down. I haven’t found a way yet to resolve this issue. If anyone knows a technique, please let me know. If the survey figure goes left to right, it’s displayed right side up. If it goes right to left, it’s upside down.
  2. The space between the text isn’t controlled by the drawing scale. If you are going to plot this at different scales, you would have to edit the style to get the spacing the same on the plotted page.
  3. It’s a lot of work.

Now, most likely, because I just created this post, the very next version of Civil 3D will have fixed the issue of linetypes for figures and feature lines but until then, hopefully this will help someone out.

Credit for this goes to Kelvin at Lamp, Rynearson & Associates