Department of Civil Engineering

Technology

BACHELOR OF ENGINEERING
TECHNOLOGY: CIVIL ENGINEERING

(BEngTech: Civil Engineering)

PRACTICAL BRIEF
Road Design with AutoCAD Civil 3D

TRANSPORTATION ENGINEERING 2A
(TRACIA2)

JANUARY - JUNE 2024

Lecturer: Mathe A. Kasenge

(Doornfontein Campus)
CHAPTER ONE
 Road Design Using AutoCAD Civil 3D
AUTOCAD CIVIL 3D 2023/4

AutoCAD Civil 3D Tutorial: Importing Survey Points

This tutorial guides you through the basic steps required to (1) import survey data into
AutoCAD and build a surface, (2) explore representations of a surface, and (3) generate a
profile of your surface.

Part I: Importing Survey Data into AutoCAD CIVIL 3D

1. For this tutorial, we will use survey data of the area next to N3 from Heidelburg to
Mpumalanga, RSA from Transportation project done by Civil Engineering Technology
students at University of Johannesburg. These survey data include a text file of survey
point which is accessible in civil 3d and other file including the picture of the location,
excel data and csv* file of the survey data. The original data was collected from Equator
LiDAR and analysed for Civil 3D and, we will explore the data in AutoCAD Civil 3D.
Download the data at this address:
Civil 3D Lab Points - ENZ.txt
After opening the zip file, download the data and store in a location where you have
permission and can easily access them.
2. Open the folder to look at the data included. The survey data files are saved as ENZ N3 to
R23 POINTS text files.
There is “ENZ N3 to R23 POINT.txt”. “ENZ” stands for Easting, Northing, Z (elevation).
Open the file “ENZ N3 to R23 POINT.txt” in a text editor (Notepad+ or WordPad or import
into Excel).
3. You will find that this file has three columns, and these correspond to (1) the Easting, (2)
the Northing, and (3) the elevation of each point (row). This file does not tell us the
coordinate system of the points or the units. In practice, you would consult with your
surveying team to obtain the coordinate system and units of these data. In this example,
the coordinates are in the Universal Transverse Mercator (UTM) projected coordinate
system with units of meters.

4. Close any open text files. We are now ready to import “ENZ N3 TO R23 POINTS.txt” into
AutoCAD Civil 3D.
5. Launch AutoCAD Civil 3D – English Metric (we know the units are in metric for this
example) from the Start Menu (as seen below). Your machine may need to install the
software – let it do so. Note: It is important that you launch AutoCAD Civil 3D and not the
original AutoCAD. Civil 3D has tools that are needed for this exercise that are not found in
the original AutoCAD.
6. AutoCAD Civil 3D will start. Close the welcome screen if it appears BY STARTING A NEW
DRAWING.

This should be the screen you have when starting a new drawing.

7. After opening a new drawing first and foremost is to set up the drawing settings
to suit the coordinate system and correspond actual location.
 - On Drawing1 on prospectus window on your left, click settings then right click on
Drawing1 to have more options. Select drawing > Edit drawing settings and set up
like shown on the picture below.

THE DRAWING SETTINGS SHOULD BE SET TO CATEGORIES > UTM, WGS84 DATUM and UTM-
WGS 1984 datum, Zone 35 South, Meter; Cent. Meridian 27d E, all this are shown on the picture
below.
8. We will first Import points. This form bases of our surface where the surveyed
points will be stored in the database. On the “Home” ribbon, click Points > Points
Creation Tools > Import points with a blue arrow on the last tap on the ribbon.

9. The Import Points dialog appears.

You should first note that there are many different format options in the “Specify point
file format” window. Many of these are intuitive: P= point number, , E = easting, N =
northing, Z = elevation, D=description. You will also note that there are different ways
to delimit the file, and these include: tab delimited, comma delimited, and space
delimited. From Step 3 (above), you should have noted that the format is ENZ, and the
columns are separated by a single space.

Hit the plus sign next to the selected files window and browse to “ENZ N3 TO R23
POINTS.txt”. The tool WILL automatically detect NEZ (space delimited), but we
need ENZ(space delimited), select it in the file format window. Make sure your
screen matches the options below and click OK.
Double click on the drawing or click zoom extends to show your survey points.

10. We will then create a Surface Definition. This is where the surveyed points will
be stored in the database. On the “Home” ribbon, click Surfaces > Create Surface.
 11. The Create Surface dialog appears. Here you can specify the name, description,
default contour style, and render material for your surface. You will be able to change
the Style and Render material later, so don’t worry too much about them right now.
Make sure your screen matches the following graphic and click OK.

12. Now we have a surface database to store the survey points, but it is currently empty.
Let’s import the survey points now. Click the Surface tap on the left > expand Surface >
NGL > Definitions > Points Groups > Add and select all and apply then OK!
AutoCAD CIVIL 3D is displaying the contours of your surface (1m minor interval, 5m
major interval). You can see a meandering road! The green boundary represents the
limits of your surface triangulation. In the next section you will explore ways of
visually representing the surface.
Part II: Representing the Surface
13. Now we will examine different ways to represent the surface. Click Modify >
Surface to arrive at the Surface ribbon. Then click Surface Properties > Surface
Properties OR click the surface as it is highlighted right click your mouse > Surface
properties.

14. The “Surface style” dropdown provides several ways of visualizing your surface.
We setup the surface to display “Contours 1m and 5m”. How else can we visualize the
surface? First, let’s examine the triangulations used to create the surface. Select
“Contours and Triangles” and click Apply.
The screen now shows how the surface was created and every triangulation calculation used
between the survey points. The denser the web, the denser the number of survey points in an
area.
Inspecting this triangulated irregular network (TIN) is especially useful if the generated
surface shows something unexpected, which may arise due to a surveying error or in areas that
are not adequately surveyed. This is an important visualization tool, because it shows the
location of your surveyed points (at the vertices of the web). You could surmise that there may
be inaccuracies in the locations with less survey points.
You can specify the shape of the boundary used to create this TIN surface. For example, you
may want to move the boundary in closer to the road where you have more survey points. This
is left for you as a future exercise.

15. Now let’s look at a raster-type representation of the surface. In the Surface
Properties dialog, select “Elevation Banding (2D)” in the “Surface style” window and
click Apply. AutoCAD should display a colourful representation of your surface, as seen
below. We expect the red areas are the lowest elevations and the blue areas are the
higher elevations, but how can we know for sure?

Note that we can also view a similar map with the slope values (“Slope Banding 2D”).

16. To answer that question, let’s return to the original representation – select
“Contours 1m and 5m (Background)” and hit Apply. An easy (and intuitive) way to find
 the highest elevations and lowest elevations is to simply label the contours. Click Add
Labels > Contours – Multiple. Note that there are several options for labelling your
surface here.

17. Click a point in the top right area and move the mouse. You will see that a line
follows your mouse. All contours that intersect this line will be labelled.

Select a second point (as shown below) and hit enter. Zooming in, we find the following:
As expected, the slope is draining from the steep to the lowest point, indicated by sides (1666
m to 1665 m elevations).

18. Now use the contour labelling tool to label the contours in the lower left extent.

Zoom in after executing this tool, and we find the following:

The contours in the lower left are around 1663 m. So this verifies that the road is
flowing here from the top right to the bottom left. (of course, you could have easily
verified this with a field trip or a discussion with your survey crew)
A final note: the contour intervals here seem too large for this dataset. You can change the
contour intervals in the Surface Properties dialogue (you will have to create a new style).
Part III: Creating a Alignment and Profile from your Surface
19. Now that you have created a surface from your survey points and explored
different ways of representing the surface visually, a useful exercise is to look at profiles
(or cross sections) of your surface. This is especially important in design work where
you are interested in how the topography varies along some path, which is called an
alignment in AutoCAD.
As an example, we will create a profile of the surface along the approximate route of the
N3 to R23 Road. To do this, we first need an alignment, which can be created from a
polyline. Zoom to the upper right part of the surface, and then type the command “pl”
to start a new polyline. Click a point where you want to begin/start the line, and then
follow the path you want to create your alignment on, clicking along the way to add
new vertices (as seen below).

Do your best to follow the path you want to align. In practice, you would probably want to pick
a more refined way of tracing the route, but we will just create the alignment manually here as
an example.

20. Once you have reached the end of your road, hit ENTER to finish the polyline.
Left click on the polyline to select it. Note: if you made a mistake, you can either edit
vertices with the polyline edit tool (type “pe”) or you can delete the polyline and start over.
21. Make sure you are viewing the “Home” ribbon. With the polyline selected, hit
Alignment > Create Alignment from Objects. Hit ENTER if necessary.

22. AutoCAD Civil 3D will ask you to verify the direction of the alignment. As seen
below, it will show an arrow pointing in the direction (look at the middle part of the
polyline). Because we drew the alignment in the direction of the flow, it should be
oriented correctly. Hit ENTER to accept the direction or reverse the direction if
necessary. Indicated on the next page.
It is important to know the direction of the alignment, as it will help you make sense of the
profile. Alignments will have stations, such that the alignment begins at a reference point
(usually 0+000 m), and the stations will be numbered based on the distance along the
alignment path from that reference point. So if we specify 0+000 as the starting point of the
alignment, a station of 0+500 signifies a point that is 500 m away from the starting point
along the alignment. Note that this is not necessarily the distance from the starting point as
the crow flies; alignments that meander (like our example) or alignments that have
curves/bends will have stations that do not correspond to the straight-line distance from
the starting point of the alignment.
After you have created your alignment, you can label the stations in your plan view to help
you remember the orientation. This is left for you as an exercise on your own.

23. After you confirm the direction, a dialog entitled “Create Alignment from
Objects” will be displayed. Here you can name the alignment, select the type of
alignment, provide a description, specify the starting station (we use 0+000.00m here)
select the drawing layer and specify other options. Make sure your screen matches the
following graphic and hit OK.
24. The alignment is now created. You can confirm this by looking at the
“Prospector” tab in your Toolspace. Expand Alignments > Miscellaneous Alignments
and find your new alignment.

25. You now have created a surface and your alignment for the road. At this stage,
the two are disjoint. Let’s sample the surface along the road alignment we just created.
To do this, select the alignment in your plan view and click “Surface Profile”. Here you
can select which alignment, and which surface you want to use in this operation. In a
real project, you would likely have many alignments (e.g., road centrelines, pipe
centrelines, channel/road centrelines, etc) and many surface (e.g., existing grade,
proposed grade). In this example, there is only one alignment and one surface.
Highlight “Surface1” and hit “Add>>”. Then hit OK to sample the surface along your
road alignment.

26. You have sampled the surface along your alignment and are now ready to
generate a surface profile. Select your alignment in the plan view and click “Profile
View”.
27. A “Create Profile View – General” dialogue will be displayed. You will now go
through a series of tabs to specify the properties and style of your profile. Make sure
you match the following graphic and click “Next >”.

28. Once you reach the “Profile View Height” page, ensure that there are values in
your minimum and maximum height boxes. If not, then you may not have successfully
sampled the surface along your alignment (Step 25) or you did not select the correct
alignment (Step 27).

For this exercise, we will not worry about the style of the profile, so we will just continue through
with the default values. Keep clicking “Next>” until you reach the “Profile Hatch Options” screen,
and then hit “Create Profile View”.
 29. AutoCAD Civil 3D will now prompt you to select a profile view origin. Zoom out
and pan away from your surveyed points, where you will likely not have any
points/features drawn in the future. Click at your desired location to place the profile.

30. The profile will be drawn automatically for you, as shown below (red line
is your surface).
Remember that station 0+000 corresponds to the top right corner of the survey, where we
started the alignment, and station 0+500 is in the lower left corner of the survey. The profile
shows the roadbed gradually sloping from 0+000 to station 0+500, which meets our
expectations. There are some jagged areas, which may have resulted from a variety of reasons:
(1) we eyeballed the alignment, (2) there may be low points or rocks in the road survey, (3)
there are locations without many survey points where we are viewing the interpolation. The
profile tool is a useful way of looking at slices of your surface, which should inform your
designs.

Note that you can also use this tool to generate cross sections (e.g., profiles that are perpendicular to the
direction of flow). It is left as an exercise for you to create a cross section of the road.