Month: September 2022

Reviewing Civil 3d Surfaces – Part 2

I often see users new to grading with Civil 3d make the same errors reviewing surfaces. Here we are going to continue our series and show you a few shortcuts to help you review surfaces faster.

I see this often with new users, they want to check the grades, and do it by copying a grade label all over the place. To review these they need to review each number. Lets supercharge this and talk about surface analysis!

Select the surface, right click and select Surface Properties.

Setup the desired # of surface analysis. I usually use this scheme:

I usually do this for the following reasons. I want to flag any slope under 0.50% as too flat to drain. Often I may want to increase this range. 0.50-1.50% I also want to check out. 1.5%-2% is flagged so we can check for any issues with ADA cross-slope. 2-8.33% is acceptable for ADA longitudinally. 50%+ I want to check for any too-steep slopes.

To get these to display, edit your surface style and make sure Slope Arrows is on (visible).

Now I can review my surface slopes by looking at the surface.

One issue you can have is the slope arrows are too/big or small.

You can change the size of the slope arrow by editing the style.

Adjust the slope arrow length as needed.

If you are printing this for review by your team, you can add a surface legend table

After selecting ‘Add Surface Legend Table’ and selecting your surface, it will ask what type of table you need. Select A for Slope Arrows. It will ask if you want a dynamic or static table.

Tin Lines Make Sense out of Chaos.

When reviewing the slope arrows, sometimes making sense out of them can be difficult. Turning on the tin lines helps make sense out of chaos.

This will conclude part 2 of this series. I will post part 3 sometime after Autodesk University in New Orleans. Hope to see you there.

To read part 1, visit this link: http://c3dk.com/2022/09/06/techniques-for-reviewing-civil-3d-surfaces-part-1/

Techniques for reviewing Civil 3d Surfaces, Part 1

Labels lie all the time in Civil 3d. You need to be aware of HOW they lie when you review drawings

I find a lot of new Civil 3d users do a good job of understanding the Surface Creation tools.  The available tools to review surfaces and the problems that can result are less understood. 

In this series, I am going to go through the tips I have for reviewing surfaces. There will be some good tips both for the newer Civil 3d user and tips experienced users can use to review drawings. Most of the issues in these posts come from actual drawings, not ones I have created to demonstrate these issues.

Tip #1, increase contour interval.
Increasing the contour interval can quickly reveal issues with the surface.  In the example image below left, that contour looks a bit funky.  Once I increase the contour interval the issue is quickly revealed.

To increase the contour interval, Select the surface, right click and select ‘Edit Surface Style’.  Go to the surface style, contour tab and increase 10x.

Here is a similar issue that is revealed with this change.

How Labels Lie

Labels lie all the time in Civil 3d. You need to be aware of HOW they lie when you review drawings. Lets take a look at this example below. Can you see the issue with the slope label below?

Circling it as below probably helped you find it, right?

Reviewing the spot elevations, clearly this isn’t 0.01%. Lets select the label…

We can see here that the grips are going past the breakline. You need to make sure that the grips for two-point labels aren’t crossing breaklines. In this case the slope to the left of the breakline is different than the slope on the right. So it averages these out. Its not good!

Two suggestions here:

First its a good idea not to make your two point grade labels any longer than they need to be. This will help you eliminate the issue like above, cause things are going to move.

Second, before putting your plan into any sort of final state, double check ALL the labels are referring to the correct surface. Select a single label, and then select similar.

Now that I have selected a single label, and select all. I want to verify that all my labels are referencing the correct surface.

That concludes Part 1 of this series. I will post part 2 in a few days. If you have a suggestion, please leave it below in the comments! Thanks!