Create Vertical Alignment
This exercise demonstrates how to create a Vertical Alignment associated with a given chain in COGO using the VPI Based Vertical Alignment design tool.
To begin open the profile dgn file, XX####_VA.dgn.
Adjust display to view the existing ground profile and profile cell that has been created. Below is an example of data that should exist before creating a proposed vertical alignment.
Next, Open the Project Manager, then go to Directory>Current Working Directory, next Select Project (.prj file) to work on, then Select OK, and then Select User [name] from Project Users menu.
Verify the proper working alignment is being used. Select Vertical Alignment tab on the Project Manager menu.
The settings menu will appear. Select Identify Cell then in the DGN select the profile cell.
Once the cell is selected it will become highlighted as shown , then accept by data point (DP) within a blank area in the drawing
The settings menu will now be populated with cell data. Verify the data is correct and then select OK. If data is not correct go to Existing Ground Profile and reestablish profile cell and existing ground profile
The Profile Generator will be invoked. Note the K Value Table shown at the top of the menu. This indicates the K Value Table that is being used. The current tables are the "KValues_2001_english. kvl" and "KValues_2001metric.kvl" for each corresponding unit. To load the proper K Value table, go to File>K Value Table.
The K Values menu will appear. Go to File> Open. At the ProjectWise file open menu select cancel or press Esc key.
The K Value open menu will appear at the default location. Select KValues_2001english.kvl (or metric unit) and then select OK. Note the default location is C:\Program Files\Bentley\GEOPAK\V8.11\bin.
The proper K Value Table will be loaded as shown. Select OK
The Profile Generator will appear with the proper K Value at the top of the menu. Next select File>.Preferences.
The Preferences menu appears. The setting below are the preferred settings. Adjust preferences then Select OK.
- Maintain Curve Length, maintains the user input while using the K Value as a design guide
- Hold Vertical Curve, may or may not be suitable for users design methods. It is recommended to NOT use
- Window Center Current VPI, centers MicroStation window at navigated VPI and can be useful when editing VPI stations and curve lengths
The Profile Generator should now be configured and ready to create a vertical alignment. To start creating profile, select Dynamic, a circle will be attached to the drawing cursor, use the drawing cursor to tentative snap in the drawing to create a beginning point of the profile, then accept. The first VPI has been place.
A view of the drawing cursor with the VPI circle.
To change the location of any placed VPI, select Dynamic button and move curser to the VPI circle to "pickup" the VPI and then reposition the VPI using the drawing curser. Or manually enter the Station and Elevation.
Once VPI has been placed, zoom out to include the area of the next VPI and select Insert >>. A VPI will be inserted ahead of current VPI, then select Dynamic to actively place the VPI using the drawing curser OR enter Station and elevation directly. To continue to create an alignment, the operation consists of selecting ;Insert>>, Dynamic , place VPI using curser, then repeat, Insert>>, Dynamic and place VPI. It is recommended to first place all VPI's and then save the profile.
Once the vertical alignment has defined VPI's, vertical curves can be inserted. To insert a vertical curve, navigate to desired VPI and Select Speed button and select the design speed. This will insert a corresponding minimum K Value and the calculated corresponding curve length.
The other design data is populated after a K value or curve length is entered. Note; choosing a design speed will populate a K value from the design K Value Table. All other parameters are calculated using the K value or curve length. The design speed indicator will also change accordingly to the K value or curve length entered. Continue to enter vertical curves to the speed button and curve length for deign parameters.
Vertical design best practices include;
- Round curve lengths to whole and even lengths. Nearest 10 feet (4 meters) if design parameters allow
- Round VPI stations to the whole station. Nearest 5 to 10 feet if design parameters allow
- When using the Profile Generator, do not use MicroStation tools
Which practice the Profile Generator is accommodating and very use full. The fields and buttons highlighted represent the the tools most often used. The overlap field only appears when there is overlap.
Save and Load Profile
On the Profile Generator menu go to File > Save Profile. This will save the current profile if it has been named. Periodic saves are recommended when working on long profiles. To load an existing profile for editing, go to File > Load Profile
If the profile has not been named the Save Profile As menu appears. Fill in the Profile field with desired profile name. Use a descriptive name. The Input File field can be changed to a user desired name. The input fire stores the creation of the profile in command format. Continuing to use the same input file will append the file with profile commands each time a profile is save.
After a newly defined profile has been created and saved .
After a defined profile has been saved