This article discusses the creation of basic grading in Civil 3D, with a focus on feature lines and their interaction based on their sites. The process includes drawing a polyline, offsetting the polyline, creating a feature line, and specifying its various attributes such as elevation, grade, or slope.
Key Insights
- The author emphasizes the importance of feature lines in creating basic grading using Civil 3D. Feature lines are integral as they interact with each other based on the sites they are placed on.
- The process involves various steps such as drawing a polyline, offsetting the polyline inward by 15 feet, and creating a feature line. The feature line creation includes selecting the site, naming the feature line, specifying its style and layer, and choosing conversion options.
- While setting the attributes for the feature line, different options can be specified like elevation, grade, or slope. The author prefers using elevation as it is easier to figure out rather than trying to remember slopes or grades.
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We'll go back. Now that we've gotten our base file all set up, we're ready to start talking about basic grading. And the backbone that I often use to create basic grading inside of Civil 3D is feature lines.
So in this lesson, we're going to be talking about feature lines mostly, and then how feature lines interact with each other based on which sites they're placed on. So let's start off by creating a basic feature line. I'm going to go ahead and build a framework to draw my feature line.
And so I'm going to go ahead and navigate into the drawing onto lot 10 right here, and I'm going to draw a polyline. So I'm going to go PL for polyline. I'm going to go ahead and snap to the four corners of the parcel.
So I'm going to go ahead and click, click, click, and then I'm going to hit C for close. Now, what I'm going to go ahead and do now is I'm going to take this polyline. I'm going to offset it in 15 feet so that I'm creating an interior line that is basically going to be my pad elevation or my pad for this parcel that we're creating right here.
Now I'm going to go up to my home tab of my ribbon bar. I'm going to go ahead and drop down feature line, and I'm going to start by clicking on create feature line. So inside of Civil 3D, when I select create feature line, I get the option for which site I would like to place it in, what the name of the feature line would be called, what the style of that feature line is going to be, what layer it's going to be on, and then what I could also choose to use my current layer, and then conversion options.
And the conversion options are for if we're creating it based on a certain object inside of Civil 3D. So what I'm going to go ahead and do is I'm going to create a new site. I'm going to go ahead and name my site dev branch because these are going to be all the sites associated with my dev branch alignment.
So I'm going to go ahead and hit apply and hit okay. Now I have a site called dev branch. I'm going to go ahead and change the name on this.
I'm going to change it to lot 10 pad, and then I'm going to go ahead and change this to my grading design style that we created in our template file. So from here, I'm going to go ahead and leave this as C topo feet. This is being pulled from our style, I believe.
We're going to go ahead and go with okay for this. I'm going to click okay, and Civil 3D is going to ask me to specify a start point. So I'm going to go ahead and click here, and Civil 3D is going to ask me to specify an elevation.
I want to go ahead and specify the elevation that I'm seeing for this contour running through my site right here because I want to be kind of cutting in here and filling on this corner. And so I'm going to figure out what that contour line is by coming over here and looking at this contour label. So I can see this is 190.
So I know that I want my elevation for this pad to be 190. So I'm going to type in 190 for my elevation. Civil 3D is now going to ask me to specify the next point or an arc by hitting A. I want to do a line.
So I'm going to go ahead and click and lock into this snap point here. Civil 3D is now going to ask me to specify a grade or a slope or an elevation or a difference or a surface or a transition. So depending on how you want to control your feature line, you can choose any of these options.
So I always have problems with deciding on grade and slope. Grade, I believe, is a grade ratio, so a two to one or five to one or something like that, whereas a slope is a percent slope. Now, like I said, I always have trouble remembering the difference between the two.
So I'm often doing a test, see which one it is, and then correct myself later if I have to. But since we're going to be creating a level pad, I want to go ahead and specify a specific elevation. Now, if you wanted to do a difference, you could type D and then do negative two or two, and it would go up or down whatever elevation difference you chose based on your original elevation point.
You can choose S and it will put that point on a specific surface and then transition will transition you from one point to another point and you will be basically going between two points. So for me, I'm going to type E for elevation and hit ENTER. I'm often using E setting my elevations rather than specifying grades or slopes or differences just because I find it easier to figure out what I'm doing with the elevations for my site rather than trying to remember slopes or grades or differences and that kind of stuff.
So I'm going to go ahead and keep the prompted elevation of 190. So I'm going to go ahead and enter. Then I'm going to move on to the next point.
I'm going to click. I'm going to hit ENTER. I'm going to move on to my fourth point, click, hit ENTER, and then I'm going to come back to this point and click here.
Simul3D now closes this feature line. It's now a closed feature line with four points that are at 190. So that is the basics of creating a feature line just by dropping down selecting create feature line.
Now that I've created this feature line, I can go ahead and select it. And from here, what I can do is I can go to elevation editor right here. If it's not popping up, it's under this edit elevations here.
If I select elevation editor, a panorama window opens up and I can see all the points associated with this feature line. And I can see that all of the actual elevations are 190 feet. So it looks exactly as I expected to be created.
All the grades are zeros. So I'm going to go ahead and check, escape out. I'm going to save my drawing and then I'll meet you in the next video.