From the course: Cert Prep Autodesk Certified Professional: Civil 3D for Infrastructure Design

Work with subassemblies and assemblies - AutoCAD Civil 3D Tutorial

From the course: Cert Prep Autodesk Certified Professional: Civil 3D for Infrastructure Design

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Work with subassemblies and assemblies

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- [Instructor] It's time to begin our chapter on corridors. Corridors are made up of three main building blocks, alignments, profiles and assemblies. You've already learned about alignments and profiles. So let's cover assemblies now. So assemblies represent the typical cross section of a road and they're made by putting together parts of the cross section called sub-assemblies. Let's see how it works. On the home tab of the ribbon I'll start by clicking the assembly dropdown and then clicking create assembly. I'll put a name in for my assembly. I'll call it main road and everything else looks pretty good. I'll click OK. Now assemblies are pretty small compared to the rest of the drawing so I usually like to put mine near the lower left corner of the profile view so I can find them later on. I'll click here. And we can see that we start with just a simple red vertical baseline. This is the heart of our assembly, and it doesn't have any form yet because we haven't added any sub-assemblies. So let's do that next. The way add sub-assemblies is to bring up your tool palettes. And you can see that I've defaulted to this basic tool palette but there are many others to pick from which all contain different sub-assemblies. And we could spend quite a bit of time going through all of the different sub-assemblies that Civil 3D comes with. Not to mention that there's something called the sub-assembly composer where you can create your own. We're going to stick to the basics with this example, and I'll start by adding not a basic lane, but a basic lane transition. And the reason I'm using basic lane transition is because this sub-assembly has the ability to be transitioned say to add a turning lane or something along those lines whereas this one does not. So this one's a bit more flexible. So I'll click the icon on the tool palette. And that brings up the properties window with all of the different parameters for my lane. Now the parameters will be different for each sub-assembly because they each represent different geometry and have different dimensions and all of that. So here we've got the width whether or not the crown point is on the inside and so on. So I'm going to go with his default width of 12 feet, the depth is 0.67. There are other sub-assemblies for lanes that are much more complex that have individual layers for the wearing surface so base base and so on. This one's pretty simple, it's just one material. Notice also the default slope. That's a pretty important one as well. So if I want to insert this on the right side, you'll notice it says left but it's also sensitive to where I click on the assembly as to which side it inserts on. So if I click on this side of the square marker that made a liar out of me, it inserted on the left. Let's try that again. I'll click over here and you can see that inserted on the right. So that gives me my lane on either side of the assembly. Let's add another sub-assembly. This time we'll pick basic curb and gutter. Again, I've got all kinds of parameters different for the curb and gutter than the last feature because it has different geometry. So the width of the gutter, the slope, the curb height, the curb width let's say we want to do a half foot curb here. So I'm going to type in 0.5 for the curb height. Then I can click either side of my sub-assembly. Notice I'm attaching this to the lane sub-assembly. So these work almost kind of like a child's building blocks the way they snap one to the other. Now I'd like to insert a sidewalk but I don't want to use the basic sidewalk because it doesn't have grass strip areas on either side. So I'm going to go to this curbs tab which has a lot of different very complex curves in it as well as this one called urban sidewalk. I'll click urban sidewalk and enter in my Boulevard widths and say I want to do two feet on either side of my sidewalk. I'll attach that to the back of the curb. And here you can see the Boulevard area on either side and then the sidewalk itself. I'll attach another one to the other curb on the other side. Now my assembly does not have to be symmetrical. I could have a sidewalk on one side and not the other. I can build the assembly exactly as I want or need to. And then for my last sub-assembly I want to actually be able to tie this in to a surface. So our profile's going to cause this assembly to be inserted above existing ground in some cases and below in others. So we need a sub-assembly that's going to tie it all back to existing ground. And I'll use this one here, basic side slope cut ditch. Now the names of the sub-assemblies as you can see, get a little bit crazy depending on what they can do in the capabilities that they have. So I'll launch this sub-assembly and you can see it has quite a few parameters. I'll go ahead and attach it to the left end of the sidewalk. And then the right end. To simplify what this sub-assembly does is it's going to find the existing ground and if it's in a cut situation, it'll use this slope and whatever cut value we've assigned here. You can see it's two to one. If it's in a fill situation, it will use this slope which currently is set to four to one. And also if it's in a cut situation it will add a ditch to intercept any drainage flowing down the cut slope and preventing it from going out into the road. It will automatically add that ditch. And we've got a bunch of dimensions and options that apply to that ditch. So that's how sub-assemblies are used to build up an assembly, which becomes the typical cross section of your road or other design feature. In the next video, we'll put our assembly together with an alignment and profile to create a corridor.

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