Join Josh Modglin for an in-depth discussion in this video Creating an advanced corridor: Cul-de-sac, part of AutoCAD Civil 3D Essential Training.
- [Instructor] Now that we get a base understanding of how to create corridors and even how to use the information to create a surface and targeting, let's go to the next step. Let's get a little bit more advanced and create a corridor object to deal with a cul-de-sac. And so that's our next exercise here. 08_07, creating a corridor for a cul-de-sac. And notice we're zoomed in to this cul-de-sac. I've provided a spot elevation here at the end of my corridor.
In fact, I pulled the corridor back, the station range for this region ends right at the beginning of the cul-de-sac. And then I've provided a spot elevation for the corridor surface, so I know. Ultimately, what that means is I have to provide information to tie this in. When we think about a cul-de-sac, the center of the road is critical. That's what's going to be staked out.
And so we need that information, we need to use that information, but ultimately, a cul-de-sac itself is its own design. Are you draining to this low point here? Or are you going to a high point here and sending all the water down the road? All these different controls that you would have, and really, you have your low point, a lot of times, line up with the property line right here, and so the edge of the cul-de-sac is really its own design. That's critical, because as we understand how a corridor is created, a cross-section of the assembly, the assembly object itself, is applied to the linear path and is always applied perpendicular to that path.
As we begin to get more skewed from that path, and being perpendicular from that path, the information becomes more and more inaccurate. More than that, once we end our center line here, we really have no more data to create the corridor on this side. We could stretch it and have our actual center line go out here, but again, you're still getting skewed information. And then when you get to this point, there is no daylight information.
So what we're going to do is we're going to add another baseline. In fact, there's already an alignment drawn in here and if I float over the alignment near the beginning, you'll see that it's named Osceola cul-de-sac, and that the station offset, my stationing is near the end. What that tells me is that my cul-de-sac alignment is going in the clockwise direction. If I place my stationing over here, notice it's 212.
So actually, it's going counterclockwise. So just getting a better understanding of the direction it's drawn, simply because you didn't draw it, and what that means is the lane, or the information that we're going to do is to the left of here. And our alignment goes this direction. We need to create a profile to deal with the drainage along this edge. We're going to add a baseline. We're going to add a corridor to this cul-de-sac. And the edge of this cul-de-sac, so we're designing this cul-de-sac so that we have the three elements: the linear path, horizontal, and vertical.
So let's do the vertical. I'm going to select the alignment. And choose to create a surface profile from the contextual ribbon. We're going to use the existing grade, we're going to assign the layer, being the existing grade profile layer. We're going to draw in profile view, and I'm not going to walk through any of these settings, we've already done it, so because my feature settings are already set to the correct defaults. I just say create profile view, and it creates the view off to the side here.
And now we have enough information that I can create a proposed profile. So I select my profile view, say profile creation tools, we're going to let it name itself, because the default settings are good. I'm not too concerned about having profile labels. I'm not doing curves and so forth, but we'll go ahead and leave that on. Click OK, and I'm ready to drill my profile. Now whenever I'm drilling a profile, because I want it to be accurate, I usually just pick a start point on the grid and an end point on the grid, using object snaps.
Now that way, I know my profile is completely the full length of my alignment. Now, if I look at the existing surface, I realize I probably am going to have some type of high point near the middle. And so what I'm going to do is, I'm going to turn off my object snaps, and I'm going to go ahead and insert a PVI. Now that's not even close to the kind of design I want done, but I have my start PVI, I have my middle PVI, and I have my end PVI.
So I have all of the PVIs I need, and the rest I'm going to use the grid view to accomplish. So I open up my grid view. I'm going to go back to the plan and look, and I realize my profile needs to start and end at the same elevation. 261.17. So my profile start elevation is 261.17, profile end elevation, 261.17.
And I look at the full length of my alignment or profile. And I'm going to try to get close to splitting that in half. So we'll go with 109, and now we're just going to make some adjustments, so that we get a nice crest and keep a clean, consistent grade in and out. So we'll make some adjustments here. So I have all of that set, let me go ahead and take a look. Here's my profile, now this profile is for the edge of the travel-way for my cul-de-sac.
So I have my alignment, I have my profile, do I have my assembly? Well, let's take a look at the assemblies we have. We created a main road assembly previously. We have a few other assemblies here in the drawing, but we're going to look at this one. It's called lane left, curb right. Notice where that vertical marker is. The assembly marker. Now remember, we had mentioned that anything to the left of that marker is going to be drawn left of the alignment.
Anything right of the marker will be drawn right of the alignment. We created the alignment right at the edge of travel-way, and so this is the correct assembly. Now, you may get confused, because you look at that road, that lane just doesn't look right, but with targeting, what we see here in our assembly is not what we're going to have as an end result. Our targeting is going to allow us to create or draw the lane at the correct slope.
Now we have all the three pieces. Let's see how all this comes together. I'm going to go back to my cul-de-sac here, and instead of creating a new corridor, I'm going to go ahead and select my existing corridor, and we're going to choose from the modify corridor panel, corridor properties. What we're adding is an additional baseline to my corridor. So we're going to say add baseline. And what are we going to use for our baseline? Is an alignment profile, our alignment, so we can select from the drawing.
There's that cul-de-sac alignment. Click OK. Now here's where you can really get lost. If you're using alignment profile, don't forget to add the vertical for that linear path. Go ahead and select that layout profile we created earlier in our exercise. So our baseline is defined, and now we're going to right-click on that new baseline and choose to add a region. A region's, of course, associated with the assembly. The assembly we're going to use is lane left, curb right, the one we were looking at previously.
It doesn't look like anything happened, but if you hit the plus sign, there's my region. And if we notice the region and the start station and the end station, all's good. The frequency's okay, but let's go ahead and check our frequency. Because all of it's on a curve, we're going to bump this up to get a more accurate look of our cul-de-sac. There's no vertical curves, so go ahead and click OK. And here's where things get fun. Go ahead and click in targeting, and we're going to walk through targeting all of these items.
First, daylighting, easy to set. We say click here to set all. Everything's daylighting to the existing ground. For our lane, this we're stretching back to the center line. So we're actually kind of flipping the idea. We're looking at the center line as our control, and it is. But instead of using the control to draw away from to draw our cul-de-sac edge, we're using the cul-de-sac edge to draw toward our control.
So we're going to use that not only for our width, using our alignments, and the alignment we're going to use is, again, the center line of our cul-de-sac, which is Osceola Road, and don't forget, once you select it to add it to the items to target. So not only for width, but also for our lane's elevations. We're going to use that Osceola Road, the profile, finish grade or layout, and make sure that's added as well.
I click OK, all my targets are added, my frequency is good, my regions are good, I click OK, it rebuilds the corridor, and what do we have? Notice how the corridor, because it's following this alignment as the baseline, is always perpendicular and follows the curvature of that cul-de-sac very cleanly. But it stretches back, at all times, to the center line. Not only the center line horizontally, but the center line vertically, allowing us to get a very clean and accurate, realistic look of how that cul-de-sac would be built.
And so, again, just to repeat, when we're working with items that begin to completely go in such a way that they're not really perpendicular to our corridor baseline or alignment, we may begin to consider creating a new baseline and using that baseline to do all of our design, and then target back to our control baseline for our width and elevation.
This course gets you up and running with AutoCAD Civil 3D. First, instructor Josh Modglin shows how to model a surface, lay out parcels, and design geometry, including the making of horizontal alignments and vertical profiles. Next, Josh demonstrates how to create corridors, cross sections, pipe networks, and pressure networks. Then, he covers working with feature lines and grading objects, and how to share your data. He wraps up by providing an overview of plan production tools.
- Navigating the Civil 3D interface
- Using point groups and description keys
- Importing survey data
- Managing figures
- Creating and analyzing surfaces
- Creating parcels
- Working with alignments
- Working with profiles and profile views
- Working with assemblies and subassemblies
- Creating Basic and Advanced Corridors
- Using an Intersection Object
- Making sample lines, cross sections, and section views
- Creating a pipe network
- Understanding pressure parts
- Creating and editing feature lines
- Creating and editing grading objects
- Sharing and referencing data
Skill Level Beginner
Some of the exercise files do not properly function.
This course was built to work with the latest release of AutoCAD Civil 3D. If you are not running AutoCAD Civil 3D 2018 there are some exercise files that will not work for you.