Widening Matching Existing Crossfall
Updated December 15, 2021
This article applies to:
- RoadEng Civil
- RoadEng Forestry
Note: the file used in this example can be downloaded here: widening example.zip
New Location Design
1. Open the Location Module (if you are running the Terrain module, you can click on Setup | Location.
2. Select File | New to open the file open dialog box.
Figure 1: File | New first prompts you to define the original ground
To create a new road alignment in the Location module, you first need to create an original ground DTM. This is usually done by reading survey data into the Terrain module, and then creating a surface with contours (see previous exercises). However, it is possible to import DTM surfaces from other applications by using LandXML or DWG (3D faces) file formats.
3. Browse for file topo.terx (included with this example) and press Open. After a moment you will be prompted with the dialog box below.
Figure 2: New Location start dialog box
The Terrain file topo.terx has a surveyed feature that represents the existing road center-line. This feature was selected to be the current feature before topo.terx was saved. In this design we wish to follow the existing alignment exactly, so we will use this feature as our initial (and possibly final) alignment.
4. Choose Terrain feature (the default) and press OK to continue.
The look of your screen depends on the contents of the default Screen Layout (Normal.dlt) in your RoadEng Settings and Layouts folder (you can find this folder in the Setup | Location Setup, Install tab).
Figure 3: The Location module after starting a new alignment
In the figure above, you can see the original ground DTM in the Plan background; the line work is faded so it doesn’t overwhelm the new alignment features. A red dash-dot line shows the alignment.
Creating a Widening Template
5. Choose Home | Templates to open the Template Editor.
The DF – Resource Low Volume template is selected because it is assigned to the current section.
6. Right click on Templates | New Template, change the name and description. Enable the Match the existing ground property.
Figure 4: Creating a New Template
7. Click on the e-Library button and select Overlays and Widenings (figure below).
Figure 5: Retrieving Components from the e-Library
8. Expand the Overlays and Widenings template to show its components (double click or click on the + button).
9. Select the Widening II - Mill & Overlay component, right click and choose Copy.
Figure 6: Copying Template Components
10. Expand the new WIDE – Widening Fixed Width template by double clicking on it. Right click and choose Paste | As New - Left.
Figure 7: Pasting Template Components
11. Select the Widening II - Mill & Overlay component, click on Properties and change ExistingACP_Offset to 3.5 and NewACP_Offset to 6.0. The old pavement width is 7m and the new pavement 12m wide.
Figure 8: Setting Values for Pavement Offsets
12. Right click on the Widening II - Mill & Overlay-Left component and choose Paste | As New - Right.
13. Repeat the steps above to copy Ditch I Standard and Slope I - Standard Cut/Fill (Left and Right) components from the Resource Low Volume template into the newly created WIDE – Widening Fixed Width template. The new template should be like the one shown below.
Figure 9: New Widening Fixed Width Template
14. Press OK to close the template editor, and respond OK to the “Recalculate Range” prompt.
Assigning the WIDE Template
We wish to widen the road on both sides only for a given station range. The widening starts at station 100 and continues to the end of the surveyed center-line.
15. Choose Home | Assign by Range and select the Templates tab.
16. In the Template Name control, choose WIDE Widening Fixed Width. In the From Stn. edit box type 100, leave To Stn. as the default “..”.
17. Press the Add/Edit button. The dialog box should appear as in the figure below.
Figure 10: Assign Parameters by Range Dialog Box
Note: The most common mistake made in the assignments dialog box is to skip the Add/Edit step. If you Press OK before the ranges are updated, nothing happens.
18. Press OK to return to the main screen. Respond Yes to “Recalculate Range”.
19. Select menu View | Jump to Station (or <Ctrl-J>) and type station 100. Press OK to update the current section (see figure below).
Figure 11: Section and Plan Views at Station 100
To avoid the sudden change in pavement width, the TP Taper template can be assigned between stations 50 and 150. Both templates: BR Bridge and TP Taper are always available in the Template Name drop- down menu.
Figure 12: Assigning the Taper Template
The Plan view should be similar to the figure below.
Figure 13: Plan View of the Width Transition
Using Reference Features
We are going to use reference features EP-0 (existing pavement edge, left) and EP-1 (right) to set the NewACP_Offset value.
20. In the plan window, hover over the blue feature to the left of the center line. A tool tips window will popup (figure below) showing that the feature name is “EP-0”.
Figure 14: Feature EP-0 (Edge of Pavement, Left)
21. Choose Corridor | Properties | Features. On Reference Terrain topo, browse and select EP-0 as shown below.
Figure 15: Reference Features Dialog Box
Now that we have defined the old pavement edge, we would also like to display it in the section window.
22. Click the Section tab.
23. Set the Intersection check box then press the Options button and set the properties as shown above. Choose Color and Symbol as shown below.
Figure 16: Assigning Symbols in Section View
24. Press OK to close the Reference Feature Display dialog box and OK again to close the Reference Feature dialog box.
25. Right click on the Section Window | Section Options, enable the Ref. Feature option.
26. On the Widening II – Mill & Overlay-Left component, set the Existing ACP_Offset to use the newly created Reference Feature 1.
Figure 17: Assigning Reference Feature 1 to Existing ACP_Offset
27. Create a second reference (RF 2) for EP-1 (existing pavement edge, right) and repat the steps to reference the right edge.
28. Respond Yes to the recalculate prompt. Your cross section should now look like the figure below. Note the blue symbol representing the old pavement edge.
Figure 18: Section View withs symbols representing the old pavement edge