Graphics Programs Reference
In-Depth Information
Analyzing Slope
Another important aspect of the terrain is the slope. Areas with very steep slopes
are difficult to navigate either by construction vehicles or the eventual occupants
of the property. Flat slopes are much more accessible, but if they are too flat, then
drainage problems often occur. One of your tasks as a designer is to ensure that
your project has the right slopes in the right areas. By studying the slopes of the
existing topography, you can locate features where slopes are good or determine
that terrain modifications will be necessary to create good slopes.
Civil 3D can display slopes in two ways. The first is to show the slopes as colored
ranges like the ones you saw in the previous section. The second is to use slope
arrows that can be color coded to indicate in what range they're located, with the
added benefit of always pointing downhill to show you the direction of water flow.
Exercise 4.7: Analyze Slope
In this exercise, you'll perform a slope analysis on a surface in your drawing.
If you haven't already done so, go to the topic's web page at
www.sybex.com/
go/civil3d2015essentials
and download the files for Chapter 4. Unzip the files
to the correct location on your hard drive according to the instructions in the
introduction. Then, follow these steps:
1.
Open the drawing named
Slope Analysis.dwg
located in the
Chapter 04
class data folder.
2.
Click one of the contours to select the surface, and then click Surface
Properties on the ribbon.
3.
On the Information tab of the Surface Properties dialog box, change
Surface Style to Slope Banding (3D).
4.
Click the Analysis tab. Change Analysis Type to Slopes, and click the
downward-pointing arrow.
5.
Click OK. Press Esc to clear the selection of the surface and zoom in
to the 3D view of the surface in the bottom-right viewport.
In the 3D image on the bottom right, the darkest reds signify
the steepest slopes. This enables you to see that the area north
of the farm is fairly flat pasture land while the area to the south of
the farm slopes dramatically toward the stream farther to the south
(see Figure 4.16).
6.
Access Surface Properties again, and change the style to Slope Arrows.
