Configuring AutoCAD Civil 3D for Land Surveying Part 1 of 2

The Survey Toolspace can be accessed via the Palettes panel on the Home tab. Once the toolspace is active, you’ll have access to both the LInework Code Sets database, and the Figure Prefix Database. These databases are stored externally (not within a drawing template) and can be shared via your network. Once you’ve properly configured each of the databases, as well as Description Keys (which can be found on the Settings tab of the toolspace and are stored in a drawing template), your “field to finish” time can be cut by hours. To get the most bang for your buck utilizing AutoCAD^® Civil 3D^® for land surveying, you’ll want to configure each of these items appropriately.

Linework Code Sets
AutoCAD^® Civil 3D^® 2010 allows you to create your own linework codes and store them externally in a linework code sets database. Linework codes such as “B” to begin a line, or “PC” to begin a curve are common in the field, but having the ability to generate your own syntax based upon the techniques used in your office is what sets AutoCAD^® Civil 3D^® apart.

The codes are fully configurable as shown below:

In the example above, notice I have replaced what would normally have been the “B” to begin a line in the Special Codes section of the dialog with a . (period), but the result is the same – the period will begin a line. In fact, if your descriptions are added to the Figure Prefix Library, you won’t need to begin a line at all, Civil 3D will do it automatically when a fieldbook is imported.

Figure Prefix Database
In the example below, numerical description are used to describe objects found in the field. “11″ is the code for a building. Notice a layer has been set, and a figure style “Standard” is in use. When a field crew describes a point located in the field as “11,” and as long as there is another “11″ later (points don’t need to be collected in order), Civil 3D automatically starts a survey figure on layer BLDG. It’s important to note that these are figure prefixes. If a point located in the field carried the code 111, or 114, figures would automatically be drawn connecting these points on layer BLDG as well. That’s why you’ll find both the 118 and 119 prefixes in the library. They are assigned a layer simply to help the surveyor organize objects within the drawing. A feature line style “NO PLOT” is applied so the figures are not displayed in the drawing.

Description Keys
You can’t set up a linework code set and figure prefix “library” without paying particular attention to “Description Keys.” Description keys are used to automatically control point appearance and some point properties when creating or importing a point into a drawing. In the figure below, notice the Code “11*” When a point with a description of “11″ (called the raw description) is imported into a drawing, the key is applied, the description is changed to the format (called the full description) as noted (BLDG $1 $2 $3), and a point style as well as a point label style are applied. Codes in the field need to be separated by a space to take full advantage of the software. When imported, each set of characters separated by a space is given a unique identifier starting with $0 (dollar sign and a zero). Each subsequent group of characters is assigned $1 through $9. $+ (the dollar sign followed by the plus sign) will display all the information described in the field in the full description. There are other options as well, and the online Help system within Civil 3D will help you utilize codes to meet your needs (look for survey, best practices in the index). Description keys are similar to figure prefixes in that a code “11″ would also be used for 12, 13, 14, 110, etc. For that, and for other reasons, you’ll want to add codes with common prefixes to your description key library. The codes could be advantageous for field crews that use MH, MHOLE, MHOLE STRM, all to describe then same thing – a manhole. “MH*” would cover all the possibilities in this case.

The following are linework code examples that will work in AutoCAD^® Civil 3D^® 2010 (like the description shown on point number 314, some will not work in previous releases):

Closing a figure
FC1 VA 313 279.571080 61.851 89.414283 “BLDG9 B”
FC1 VA 314 228.405718 51.821 89.381046 “BLDG9 RT 100 50 25 -25 50 25 CLS”

Shot 313, the first shot above, will begin the side of a building. Notice in this case the B is allowed after the description for the first time. The next shot on point 314 continues the first side, and then turns right, continues 100 feet, turns another right and continues for a distance of 50 feet, and then right again for a distance of 25 feet. The minus sign is the designator for a negative right turn, but for all practical purposes, signifies a left turn for a distance of 25 feet. This is followed by distances of 50 right, 25 foot right, and finally the CLS code closes the figure. In effect, this is an 8 sided figure completed with 2 shots.

Import ASCII File With Figure Commands
A simple text file (e.g. PNEZD comma delimited) can now be modified to contain figure commands, and imported to the survey database. In the past, we called this special file a “User-Defined ASCII file” and we converted it to an “Autodesk-Softdesk FBK with Linework” using Survey Link. This is no longer necessary, you can directly import the text file. Look for Import Events in the Survey Toolspace. Once you’ve imported a text file or a fieldbook, and you’ve found errors in the drawing, simply modify the file, save it, right click on the import event, and re-import the data.

One Point, Two Descriptions
A single point can have two or more descriptions, such as the case when a power pole meets with an overhead electric line, or the back of curb meets the edge of a sidewalk.

12,5390.9371,5284.2997,0.00,PP OE1 BC1 SDWK

As long as EP, OE, BC and SDWK are defined in the Figure Prefix Database, each of the codes above will begin a unique line.

Two Different Descriptions, Create Figure Between
A single point can be connected to any other point – even if the descriptions don’t match:

10,5390.9371,5248.2997,0.00,CL1 (start a line CL1)
11,5374.9371,5248.2997,0.00,BOC2 BC (any shot taken from anyplace)
12,5390.9371,5284.2997,0.00,CL1 B CL2 CPN10 (continue the line along CL1 and begin CL2. Connect this point to point number 10 with a figure)

Points Don’t Need To Be Collected In Numerical Order
Points can now be collected out of order, so to speak, and a line can be properly drawn. For example, on a combination of shots that includes a PC, a POC, and a PT, the POC can actually be shot first:

15,5374.9371,5320.2997,0.00,BOC3 / (take the shot at a POC and escape)
16,5374.9371,5368.6031,0.00,BOC3 RPN15 BC (shoot PC and begin curve, recall point 15 as a POC)
17,5390.9371,5368.6031,0.00,CL1
18,5406.9371,5368.6031,0.00,BOC1
19,5369.0793,5262.4419,0.00,BOC2
20,5369.0793,5306.1576,0.00,BOC3 (PT of curve)
21,5354.9371,5300.2997,0.00,BOC3 (end of figure tangent to curve)

B or BEG Not Necessary To Begin Linework
Either as part of a description (the SDR33 method), or part of a note (the TDS method) – you do NOT need to begin a line with a B or BEG. As noted above, simply create a figure prefix in the figure prefix database (e.g. CL or BC, etc.) and Civil 3D will automatically draw a figure for you. As shown below, power poles are not part of a figure, but overhead electric lines are. Therefore, create a OE figure prefix, but don’t create a PP prefix, Civil 3D will handle it properly (notice two descriptions for the same point):

35,5361.1258,5085.0737,-99999,PP OE
36,5361.1258,5153.3914,-99999,OE
37,5361.1258,5221.7092,-99999,OE
38,5361.1258,5290.0269,-99999,OE
39,5361.1258,5358.3447,-99999,OE
40,5361.1258,5426.6624,-99999,PP OE

Again, you can still use the commands you’re used to, you just no longer need to.

Create Offset Figures
Horizontal and vertical offsets can be created in the field:

15,5374.9371,5320.2997,0.00,BOC3 / (midpoint of curve shot first – escape, don’t start a line yet)
16,5374.9371,5368.6031,0.00,BOC3 H0.5 H2 RPN15 BC (shoot PC, Civil 3D sees the second BOC3 code and starts the figure here instead of point 15- offsetting the figure 0.5′ and again at 2 feet as it is created, the BC command denotes the figure will be a 3 point curve)
17,5390.9371,5368.6031,0.00,CL1
18,5406.9371,5368.6031,0.00,BOC1
19,5369.0793,5262.4419,0.00,BOC2
20,5369.0793,5306.1576,0.00,BOC3 (last point, or PT of the curve)
21,5354.9371,5300.2997,0.00,BOC3 (creates a line tangent to the curve)

Use Description Keys To Filter Out Commands
Description keys can be used to filter long descriptions, i.e. enter a code of BOC* with a format of BOC (the full description), and for each BOC shot, regardless of the complexity of the figure commands, the full description will be denoted in the drawing. I typically use the $+ format in a description key to show the entire description. You’ll have a better shot at deciphering what was collected in the field, and you’ll see any notes that were added as part of a description as shown below:

17,5390.9371,5368.6031,0.00,CL1 26BB

The above description is typically how I would code the centerline of a road that’s 26′ wide from back of curb to back of curb.

As a reminder, the commands noted above can be used in any description. So whether the file you’re importing is a text file exported from a data collector, a LandXML file exported from a data collector, or a fieldbook created in any number of ways, is of no consequence.

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Civil 3D Library
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