Using Civil 3D Expressions with Profile Design Check Parameters

While our last post looked at using an Expression to control the labels of our pipe lengths which is typically used at the final drawing production stage, this post deals with using Expressions to help at the preliminary design stage.

Here is the scenario...

The client is working on a 15 kilometre road reconstruction project that has a lot of vertical grade difference and needs to identify areas of the existing road that has a vertical grade of 6% or greater that may be considered for improvements based on the jurisdictions requirements.

How do we quickly identify these areas on a Civil3D profile?

By using the Expressions dialogue box and the Profile Design Check Set functions !

Here's how we do it.

Once you have your Civil3D Surface Profile and Profile View created select the profile and right click>Profile Properties.

Click on the Design Criteria tab and check the Use design criteria file check box

Click on the Create New in the Use Design Check Set section

Set the Type to Line and select then the Create New button from the pull down

Enter a name for the Design Check

Using the Insert Properties and Functions buttons add the following in the Expressions section and click OK

We should have the slope percent in degrees so lets enter into our Expression the equivalent of 6% in degrees which is 3.43363.

Click the ADD button to add it to the set



Click Apply and OK twice.

Select the Profile, right click and select the Edit Profile Geometry command and from the Profile Grid View button the violations will be displayed.

This Expression will check the profile and flag as a violation any grade greater than 6% or greater than -6%.

Don’t forget, even though we used Expressions this is still a Design Check so the function will be located under the Design Check Sets of the Profile Settings.

Stay tuned for more fun with Expressions!!

dh