Understanding Civil 3D elements

Now that we’re getting a little more familiar with the various access points to locate our tools, let’s try to get a better understanding of the overall functionality and capabilities of Autodesk’s Civil 3D. The way this BIM design authoring tool is built allows for multiple design geometry and components to be linked dynamically and, in a way, speak to each other. When one component is updated, it can potentially affect many other components that are built on top of it.

When you think about building a house, you start with a foundation, then you typically frame the house on top of the foundation, and then finish with the walls, roof, doors, windows, insulation, and so on. Thinking about how this workflow applies on the civil engineering side, we typically start with a survey, next we’ll lay out our proposed site geometry as the framework, and then build everything else based on this framework (roadways, utilities, etc.).

Within Autodesk’s Civil 3D, we can create the following intelligent components that have the potential to be linked dynamically to each other:

• Points
• Surfaces
• Sites
• Alignments
• Profiles
• Sections
• Pipe networks (gravity utility networks)
• Pressure networks
• Corridors

Putting each of these in the context of the previously mentioned constructional workflow, each of these components identified in the list is a stepping stone to the next component. If we start with points (surveyed or proposed), we can ultimately create a surface from those points. If a surface is created from those points, and we change the elevation, the surface will dynamically change as well.

Sites, alignments, profiles, and sections would be in closer alignment with the framework concept where we are establishing, or designing, some basic site geometry that our BIM design model will be built on top of, acting as more of a guide.

Then we get into the heart of the design matter, where we jump into pipe networks, pressure networks, and corridors. Yes, we can design some of these BIM design components without establishing the foundational and framework elements, however, we would truly be limited in what we can do from a design standpoint.

That said, we would essentially be setting ourselves up for a lot of questions that can’t be answered later on down the road. By establishing the foundational and framework elements first, we are not only setting ourselves up for a more successful design but also giving ourselves the ability to answer questions about our BIM design models at any given point in time. A thoroughly constructed BIM design model will give you the benefit and assurance in the long run that what is displayed in the drawing area can actually be constructed.

With that, we should have a fairly decent glimpse into how Civil 3D design elements function and how each is, in a way, connected to each other and can truly impact a BIM design.