Graphics Programs Reference
In-Depth Information
▶
7.
Click one of the colored areas to select the surface, and then right-click
and select Display Order
➢
Send To Back.
This displays the fea-
ture lines and other
drawing graphics on
top of the colored shad-
ing rather than hidden
beneath it.
More about Slopes
Slopes are a significant aspect of land development design. For every project,
certain slope ranges are targeted for specific purposes. These ranges can vary
from project to project.
For the example project, you're interested in knowing where there are excessively
flat areas (yellow, 0%-2%), because those areas could potentially have drainage
problems. Yellow areas on building pads are OK because there will be buildings
in those locations; but yellow areas on roads could represent drainage issues.
Green areas (2%-10%) represent slopes that can be traveled safely on foot or
with a vehicle. You want the entire road surface to be green, and there should
be enough area between each building pad and the street to install a driveway.
Orange areas (10%-34%) represent places where travel isn't possible but where
the slopes are still stable and safe from collapse. In this project, you would expect
the pond embankments and the backs of some of the lots to be orange. Orange
areas on the road and entire front yards that are orange aren't acceptable.
Finally, red areas represent slopes that are too steep for the soil to support.
These areas would be subject to collapse and are considered dangerous. Red
areas must be removed.
If the Edit Elevations
panel isn't visible, click
Edit Elevations.
▶
8.
Press Esc to clear the previous selection. In the upper-right viewport,
click the blue rectangular feature line at the center of lot 70. On the
Edit Elevations panel of the ribbon, click Raise/Lower.
▶
9.
When you're prompted on the command line to specify an elevation
difference, type
-5
(
-1.524
) and press Enter.
After a pause, the surface rebuilds, and the red area in lot 70 is
removed. The front yard is still green, which means it's in the slope
range to install a driveway (see Figure 18.7).
You may need to redo
steps 2-6 to reestablish
the ranges and colors.
10.
Save and close the drawing.
You can view the results of successfully completing this exercise by opening
Analyzing Surfaces - Complete.dwg
.
