Lesson 10: Basic Road Design with Volumes

1   First we need to open an example drawing supplied with Carlson. Issue the File Open command and choose EXAMPLE2.DWG. It should be in the Carlson work folder, and will look like the example (without the curved road).

2   Draw Road Centerline. Issue the Draw > 2D Polyline command and generate the road centerline as shown below. In this case it was drawn from the left, down and toward the right. Include a curve segment with the Arc option of the command.


3   Profile from Surface Entities. Now we will make a profile file, *.pro. This will be from the centerline shown in the drawing as the lines with the curve. Under the Profiles menu choose Create Profile From ...,  then Profile from Surface Entities. This will create a new file. Type in a file name in the dialog and click Save. On the next dialog, we will use the default values and click OK. Pick the centerline, and without hitting enter, select all of the contours. The data is written to file.

4   Draw Profile. This will give us a profile view of the contours at our centerline. Under Profiles, go down to Draw Profile and open our new file. The window will appear as shown. With the horizontal scale set to 50 and the vertical scale set to 5, there will be a 10X vertical exaggeration of the profile. Fill this dialog box it out as shown below and click OK. 

Next, there is the Profile Grid Elevation Range dialog. Accept the top and bottom elevations it gives by hitting OK. Pick a spot in the drawing to draw the profile, then view the profile on the grid by zooming as required. Your profile should look similar to this.

5   Design Road Profile. Now we will design how the road centerline profile will be, in relation to the existing ground (which is the first profile we have made). This routine will create another Profile file. Under Profiles, go to Design Road Profile, and then Design Road On Profile Grid (this method is suggested for this tutorial).

The following dialog box will appear. Since we followed up the Draw Profile command with this one, it was able to determine proper startup values for the dialog.

Choose OK on this dialog. A new file creation dialog box will appear, asking for an output file name. Enter a name such as DESIGN, and click Save.

Pick Lower Left Grid Corner <0.00,0.00>[endp on]: Pick Lower Left Grid Corner of the profile grid (Carlson has endpoint osnap active to make the pick accurate).

At this point another dialog will appear in the upper left corner. Initially, it will display only station and elevation. Once a beginning point has been designated, it will also display the relative difference from the last point to the cursor position. This can be an aid in determining acceptable slopes for your design.

Enter a station or pick a point (Enter to End): END of (pick the left-most endpoint of the existing ground profile as a tie in point). The following dialog will appear, choose OK to accept the defaults.

Station of second PVI or pick a point (U,E,D,Help): 1111.01
Percent grade entry/<Elevation of PVI>: 1999.37
Station of next PVI or pick a point (U,E,D,Help): 1911.64
Percent grade entry/<Elevation of PVI>: 2002.66
View table/Unequal/Through pt/Sight dist/K-value/<Vert Curve Length>: 500.00
For Sag with Sight Distance>VC and Vertical Curve => 500.00
Sight Distance => 2334.40, K-value => 243.2
Use these values (<Y>/N)? Y
Station of next PVI or pick a point (U,E,D,Help): END of (pick the far-right endpoint of the existing road as a tie in point).

The following dialog appears. Choose OK to accept the defaults.

View table/Unequal/Through pt/Sight dist/K-value/<Vert Curve Length>: 500.00
For Sag with Sight Distance>VC and Vertical Curve => 500.00
Sight Distance => 1000.00, K-value => 697.0
Use these values (<Y>/N)? Y
Station of next PVI or pick a point (U,E,D,Help): press Enter

At this point the following dialog appears. Change settings to match, and choose OK.

Pick vertical position for VC text: pick a point above the top of the grid

Carlson will now finish the road design, and your drawing should like the following:

6   Polyline to Centerline File. This step will create a centerline file necessary for the final road design routine. We will do the simplest variation, which is simply picking a polyline. There are other methods to design a centerline. They are documented in the manual.

First (if necessary), zoom back to the plan view area, as we will be working with the polyline first created in this exercise. Go to Polyline to Centerline File command, under Centerline, and name a *.cl file to create.

Beginning Station <0+00>: press Enter
Polyline should have been drawn in direction of increasing stations.
Select polyline that represents centerline: pick the plan-view polyline

Station      North(y)        East(x)         Description
0.0000       159460.9658     1857580.2082    LI

446.2825     159541.3445     1858019.1926    PC

1178.1130    159254.1689     1858643.2229    LI

2707.2962    157932.5436     1859412.4483    LI

Press ENTER to continue. press Enter

7   Input-Edit Section Alignment. Now we will layout the alignment for our cross-section file. This step gives the section interval, and the offset left and right from our centerline. Under Sections, go to Input-Edit Section Alignment. Choose the New tab, which brings up the dialog to make a new MXS file (multi-xsection file). Type in a new name and click Open. Notice how all files can have the same name in this road design portion, as they all have a unique file extension. So for the organization of various jobs, it is sometimes helpful to have all of the files with the same name.

Polyline should have been drawn in direction of increasing stations.
CL File/<Select polyline that represents centerline>: pick the centerline polyline
Enter Beginning Station of Alignment <0.00>: press Enter  

The dialog will appear as shown, enter in the stations and offsets exactly as they appear here. This will give the needed detail for the road design routine.

Choose OK, and another window appears that allows for any station editing or changes. It all looks good here, so hit Save.

The Alignment file is now written. There is now a preview of the section alignment lines shown on the centerline. These are just images, if the drawing is regenerated, they will disappear. (They can be drawn permanently if desired.)

8   Sections from Surface Entities. Next, we will create the actual section file (*.SCT) from the contours, in combination with the alignment file (*.MXS). Under Sections, go to Sections from Surface Entities. We will use the contours and breaklines for surface elevations, as we did with generating the profile. Specify the MXS file that we just created to read for the alignment. Click Open to select it. Then choose a new file name for the section file, and click Open.

We’ll enter in a distance of 1000 feet to add to our MXS limit of 70. This will search farther for contour elevations, then choose OK. Now, select the surface entities which are the contours and the breaklines. Once you are back to the command prompt, you are done with the making of sections.

9   Design Template. Let’s design a wide boulevard, 30’ of drivable pavement, with curb and gutter on the outside. Whenever a cut is within rock, the cut slope will go from a typical 2:1 to 0.5:1. At the top of rock, the cut will continue on at 2:1. In fill, the condition will be 3:1in all fill under 6’ and 2:1 in all fill over 6’ in depth. Pavement depths will be 8 of stone and 4 of asphalt.

First, Select Design Template, found under Roads, within the Civil Design module of Carlson. Click on the New tab.

We'll give it the same name as the drawing. Choose Open. A large dialog box appears as shown below. In it, you enter segments of the template, which work outwards from the middle as you add more lanes, curbs and shoulders. We will enter a symmetrical template, with 13.5’ pavement sections either side of centerline, connecting to a 2’ curb and gutter, with 18" of gutter and 6" of curb. Then we’ll add a 6’ shoulder.

For the lanes, click the Grades icon. This leads to a child dialog as shown next:

Fill out as shown. Its important to note that a downhill pavement from a crown in the middle is entered as a negative slope. That is, it is 2% heading from centerline outward, regardless of which side of centerline we are speaking of. Slope is in reference to the centerline of the template, and it is independent of the profile grade point. It is also important to enter an ID whenever requested. ID’s can be referenced later.

A break point in a shoulder in superelevation could be defined as occurring at EP+3, as opposed to the exact offset distance from centerline.  The advantage of EP+3 is that if the road lane width expands (e.g. for a passing lane), but the shoulder always breaks 3 feet beyond edge of pavement, then EP+3 is the only effective way to reference the break point. Now click OK. You’ll note that the lanes show up in the preview window at the top.

Next, we will add a curb. Click the Curb icon. Fill out as shown:

It is especially a good idea to match crown -- to make the curb match the slope of the last pavement lane (2% above). But if your curb tilts downward more (like 3%), then use a Special Base Slope Type. If it is flat, by all means click on Flat Base. Now click OK. Here’s what our screen looks like so far:

Next, we will add a shoulder, going uphill at 4% for 8’. Notice what is happening. You are lit up on the Curb line, so if you add another Grade, it will append after the curb, and add to the back of curIf you were to click on the GRADE: 13.500, -2.000%, EP line, highlight it, then click on GRADES, you would add a second lane before the curb. Now click on GRADES. Fill out the dialog as shown:

That’s it for the surface!  Here's what our screen looks like now:

Now we have subgrades and outslopes still to consider. Let’s turn our attention to subgrades. Let’s think about this: if our pavement is a total of 12 deep (8 stone, 4 asphalt) and our concrete gutter is 6 deep, then the stone will run 6 deep under the gutter. Do we want this stone to come back up at the back of the gutter, behind the gutter, or even wrap around back into the gutter, like a layer of bedding that is covered by dirt. The most complex concept is the wrap around, so let’s go for it.

Select the Subgrade icon, second from the right (yellow color). We’ll do two subgrades: first asphalt, which will run straight out and hit the curb, and then stone, which will run out, go under the curb, and wrap back.

For any sub-grade, we still do the vertical offset as a negative distance (negative meaning down). But follow this concept: we start it out 13 feet from offset 0, and keep going at "Continue Slope" until it hits something (the curb). This won’t work if there is nothing to hit. But it will run into the curb. Or if there is a fill slope, downhill 6:1 recovery zone lane, or something to intersect, it will also. This Continue Slope concept works perfectly for shallow asphalts and concretes that will bump into a curb, when extended.

Complete as shown above, and click OK.

Now for the other subgrade: the stone beneath the asphalt. Follow this: if the stone can’t Match Surface (note this option under Slope Type), it will start up hill with the shoulder as it passes beyond the curb (it goes out 17’). So it must have a Special Slope Type, the same 2% all the way. The Wrap Height is the vertical rise at the end of the 17’, before it wraps back and hits the curb. Select the Subgrade icon again (second from the right).

Fill out the Sub-Grad Dimensions dialog, as shown above, and click OK. Note the preview screen:

We still need to enter the outslope conditions. They are done with the Cut and Fill icons. Fill is easy in our example. Click on Fill.

Just 3 entries total: 3 (for 3:1), 6 (up to 6’), then 2 (for 2:1 over 6’). Click OK. Next, click the icon for Cut.

This is actually easier (in terms of total entries). Just 2 entries do it: 2 (for 2:1 normal cut) and down below, 0.5 (for 0.5:1 cut when in rock). Click OK.

The template is complete, so click Save. Now let’s prove we have a good template by doing the command Draw Typical Template.

10  Draw Typical Template. The file extension for templates will be tpl. Select Draw Typical Template under the Roads pulldown menu, select Example2.tpl (or as named above), choose Open and the following dialog shown here is displayed:

We have doubled the text scaler to 0.5 for better appearance in this tutorial. Click on Draw, and pick a starting position point. Here is the look of the plotted template.

11  Drawing Explorer. As more files are created, edited, loaded and reviewed within a work session, the drawing ini file takes note. You can review your active files as you work, or days later, because they save to the ini file that shares the same name as the drawing file. To see the files associated with this tutorial drawing file, select Drawing Explorer by sliding over from Project, under the Settings menu.

12  Input-Edit Section File. Input-Edit Section File has many uses. One of them is to translate or lower the elevations of a file and re-save. If we lower the elevations of our ground sections 8 feet, we can call that the rock line. Rock lines react with templates and profiles to create rock cuts and rock quantities, within the final step, which is called Process Road Design (Step 13). Select Input-Edit Section File under the Section pulldown menu. Under the Existing tab section, select the SCT file you created earlier and click Open.

The next dialog that appears is shown below:


Click the Translate button. The Translate Selections dialog appears. The Ending Station might differ from what is showing here, but it should be close to this value. Make sure the rest of the dialog looks that same as shown below, and click OK.

Now back at the Input-Edit Section File dialog, click Save As, and enter a different name, such as Rock, and save the file. Then click Exit.

Input-Edit Section can do much more through the Edit option. In the case of Edit, you would first highlight one station, then click Edit to review and revise it.

13  Process Road Design. This is the routine that weaves everything together. Select Process Road Design, as the lower command under the Roads pulldown in the Civil Design module. Fill out the dialog as shown below. Be sure to select, under Specify Output Files, the Section File option and click New. Enter a new file name and Save. Then click OK.

On the next dialog, be sure to click on Triangulate & Contour at the lower left of the dialog.

Now click OK. Here is a partial view of the final report, with itemized quantities:

Click Exit when finished reviewing the report. You will get this command prompt:

Trim existing contours inside disturbed area [Yes/<No>]? press Enter

Here is the resulting graphic, in 3D, obtainable by using 3D View Window, found under the View pulldown:

This completes the Lesson 10 tutorial: Basic Road Design with Volumes.