Join Jon Michael Roberts for an in-depth discussion in this video Creating your first alignment, part of Learning Civil 3D.
After surfaces, alignments are the next step in the chain of Civil3D objects. They will assist you in establishing horizontal geometry that you need to define. Either to establish road ways, known as corridors, or even just simple cross sections. Alignments can also be used in the design of parcels within a site. In this video, we're going to create our first alignment. So, I've imported geometry that was provided by the surveyor.
Included in is this center line, which is just a poly line that is describing the center line of the road. So, to convert this into an alignment, I'll go to my Menu ribbon, to Alignment, and Create alignment from objects. It's going to ask me to select the first line, so I'll choose my poly line. Now here it's going to ask me for an alignment direction. This is used in determining which end of this line is where the alignment stationing will start. I can either accept it based on this visual cue from an arrow or click on the reverse.
In this case, this is fine, so I'll just hit enter. So, it's going to ask me for an alignment name. I'm going to change this to Main Street, center line. The type of alignment is the center line. To start off with, I'm going to put this in the property site where all of my parcels and parcel lines are being established. The alignment style I want to use is one of existing, because this is an existing road. I don't need to do any conversions such as adding radiuses between tangents, because the design of the road is already established.
So, I'll uncheck this. And lastly, it's going to ask if I want to erase existing entities. In this case I do, because I have no need for the poly line now that the alignment is created. When I click okay, the poly line is automatically converted into an alignment. If I zoom in to this end, you'll see that the stationing now starts at zero, zoom extents. Also, notice that the parcel numbers now are two. Here's one, and two.
That is because this alignment was created into the site identified as property, and all new alignments in that site are considered parcel lines. And therefore, the parcel is divided into two parcels. So, we've now created our first alignment.
- Understanding the Civil 3D interface
- Creating parcels and right-of-ways
- Importing site data
- Designing a 3D surface
- Creating alignments and profiles
- Grading surfaces
- Creating corridors
- Designing pipe networks