Loading Your Files
9. Go to Start>Programs>Bentley>InRoads Group XM and load the product “Bentley Rail Track”.
10. From
rail_tutorial.dgn 11. Click File > Open.
12. Set the directory to Files
13. Select 14. Select 15. Select
16. Click Cancel to dismiss the dialog box.
Completing a Vertical Alignment using
Multiple Element
Regression Analysis (MERV)
In this topic, you will complete a vertical alignment that contains two previously connected elements. The alignment serves as a railroad bed. You will accomplish this task using the multiple element regression analysis command. Regression analysis allows for a best fit geometric solution through
surveyed points.
Before Getting Started
Locate the tutorial data in C:\Program
\Bentley\Tutorials\Rail. Extract RailChapter13.exe Loading Your Files
Go to Start>Programs>Bentley>InRoads Group XM and load the product “Bentley Rail Track”.
From C:\Program Files\Bentley\Tutorials\Rail rail_tutorial.dgn or rail_tutorial.dwg file.
Click File > Open.
Set the directory to C:\Program Files\Bentley\Tutorials\Rail.
Select railm_tut.xin, and click Open.
Select existing.dtm, and click Open.
Select singletrack.alg, and click Open.
Click Cancel to dismiss the dialog box.
Completing a Vertical Multiple Element
Regression Analysis
In this topic, you will complete a vertical alignment that alignment serves as a railroad bed. You will accomplish this task using the multiple element regression analysis command. Regression analysis allows for a best fit geometric solution through
RailChapter13.exe.
Go to Start>Programs>Bentley>InRoads Group XM and Rail open the
Using Multiple Vertical Element Regression Analysis
Begin this
vertical alignment.
1. Click Geometry > View Geometry> Active Vertical.
Notice there are 2 linear elements and 1 parabola in the project. Next, you will place the final linear element in the vertical a
2. Click Geometry > Vertical Regression > Edit/Review Regression Points.
3. Click the Select button.
4. In the graphic view, select points 128 to 163.
Note
dialog box. If you select points using this
must also click the Edit button; and select Yes to include all the points in the analysis, and verify that all other points are set to No:
5. Accept the points.
The points are highlighted in the dialog box.
Using Multiple Vertical Element Regression Analysis
Begin this task by reviewing the existing elements in the active vertical alignment.
Click Geometry > View Geometry> Active Vertical.
Notice there are 2 linear elements and 1 parabola in the project. Next, you will place the final linear element in the vertical alignment.
Click Geometry > Vertical Regression > Edit/Review Regression Points.
Click the Select button.
In the graphic view, select points 128 to 163.
Note Remember, you can also multi-select the points in the dialog box. If you select points using this method, you must also click the Edit button; and select Yes to include all the points in the analysis, and verify that all other points are set to No:
Accept the points.
The points are highlighted in the dialog box.
Using Multiple Vertical Element Regression
task by reviewing the existing elements in the active Click Geometry > View Geometry> Active Vertical.
Notice there are 2 linear elements and 1 parabola in the project. Next, you will place the final linear element in the Click Geometry > Vertical Regression > Edit/Review
select the points in the method, you must also click the Edit button; and select Yes to include all the points in the analysis, and verify that all other
6. Click Geometry > Vertical Regressi Regression Analysis.
7. For Element Type, select Line.
8. For Save Order, select Last Element.
9. Click Compute; then, save.
The element is placed in the alignment.
10. Click Close.
Next, you will complete the alignment by connecting the last two
analysis.
11. In the Edit/Review Vertical Regression Points dialog box, click Select.
12. In the graphic view, select points 101 to 129.
13. Accept the points.
Click Geometry > Vertical Regression > Single Element Regression Analysis.
For Element Type, select Line.
For Save Order, select Last Element.
Click Compute; then, save.
The element is placed in the alignment.
Click Close.
Next, you will complete the alignment by connecting the last two elements with a parabola, using regression analysis.
In the Edit/Review Vertical Regression Points dialog box, click Select.
In the graphic view, select points 101 to 129.
Accept the points.
on > Single Element
Next, you will complete the alignment by connecting the elements with a parabola, using regression
In the Edit/Review Vertical Regression Points dialog box,
14. Click Geometry > Vertical Regression > Multiple Element Regression Analysis.
15. Under Beginning Element, click Select.
16. Click on the preceding circular element.
17. Under Ending Element, click Select.
18. Click on the last element.
Click Geometry > Vertical Regression > Multiple Element Regression Analysis.
Under Beginning Element, click Select.
Click on the preceding circular element.
Under Ending Element, click Select.
Click on the last element.
Click Geometry > Vertical Regression > Multiple Element
19. Click Add After.
20. For Type, select Parabola.
21. For Length, type 450.00. Press TAB.
22. For the K value, type -210.00. Press TAB.
23. Click Apply; then, click Close.
Notice that the final parabola parameters are displayed.
Next, you will specify that this connection will be done using regression analysis. Set this option on the Advanced tab.
24. Click Advanced.
25. Click to turn on the Use Regression Analysis option.
26. Click the Main tab.
27. Click Free for all elements. Regression analysis requires a minimum of 3 free elements or parameters.
28. Click Apply.
The parabola is regressed through the selected the connection is made. Notice the actual length was computed.
Notice that the final parabola parameters are displayed.
Next, you will specify that this connection will be done using regression analysis. Set this option on the Advanced tab.
lick Advanced.
Click to turn on the Use Regression Analysis option.
Click the Main tab.
Click Free for all elements. Regression analysis requires a minimum of 3 free elements or parameters.
Click Apply.
The parabola is regressed through the selected the connection is made. Notice the actual length was computed.
Notice that the final parabola parameters are displayed.
Next, you will specify that this connection will be done using regression analysis. Set this option on the Advanced
Click to turn on the Use Regression Analysis option.
Click Free for all elements. Regression analysis requires a
The parabola is regressed through the selected points and the connection is made. Notice the actual length was
29. Click Save.
30. Click Report.
Review the regression results. You can save results to a file or print it.
31. Close all dialog boxes.
32. Fit the profile in the view.
33. Click File > Save > Ge
Reviewing the Vertical Alignment
Now is a good time to review the content of the alignment. You can review the entire alignment or check the tangents element by element.
1. Click Geometry > Review Vertical.
2. In the
This option displays individual elements within the alignment.
3. Click the Next button to move along the alignment.
Notice that as you move along the alignment, the element is highlighted in the graphics file.
4. Take a few minutes
the Last, Previous and First buttons to navigate elements in the file.
Click Save.
Click Report.
Review the regression results. You can save results to a file or print it.
Close all dialog boxes.
Fit the profile in the view.
Click File > Save > Geometry Project.
Reviewing the Vertical Alignment
Now is a good time to review the content of the alignment. You can review the entire alignment or check the tangents element by element.
Click Geometry > Review Vertical.
In the Mode section, click Element.
This option displays individual elements within the alignment.
Click the Next button to move along the alignment.
Notice that as you move along the alignment, the element is highlighted in the graphics file.
Take a few minutes to review the alignment. You can use the Last, Previous and First buttons to navigate elements in the file.
Review the regression results. You can save results to a
Now is a good time to review the content of the alignment. You can review the entire alignment or check the tangents element
This option displays individual elements within the Click the Next button to move along the alignment.
Notice that as you move along the alignment, the element to review the alignment. You can use the Last, Previous and First buttons to navigate elements
5. In the Mode section, click Alignment.
6. Click Print (optional).
7. Click Close to dismiss the dialog box.
8. Using your CAD software, save the rail_tutorial.dwg
9. Click File > Exit and exit your CAD software or continue to Chapter 14,
In the Mode section, click Alignment.
Click Print (optional).
Click Close to dismiss the dialog box.
Using your CAD software, save the rail_tutorial.dgn rail_tutorial.dwg file.
Click File > Exit and exit your CAD software or continue to Chapter 14, Creating a Cant Alignment.
rail_tutorial.dgn or Click File > Exit and exit your CAD software or continue to
13
Overview
While several other tutorial topics discussed creating vertical and horizontal alignments with multiple element connection and regression ana
cant alignment from an existing horizontal alignment. In rail design, the cant (angular tilt of the track) alignment is
necessary to counteract the centrifugal forces imposed in a horizontal curve.
Cant is analo
design) and the terms are frequently used interchangeably.
While a single (parent) horizontal alignment is required, it may actually have several cant alignments associated with it.
These various cant alignments
different design alternatives for a rail project.
Typically, a geometry project is established, including creating or loading a horizontal alignment. Cant alignments can then be created based on the existing horizontal elemen
Bentley Rail Track, a cant alignment is created in two ways: 1) values are computed by an equation using various design parameters that you provide or 2) cant values for each station are selected from an ASCII file lookup table, which contains radius and cant values. Once cant values are available, the Cant Alignment Editor command allows you to add to or modify these values.
In this task, you will create a cant alignment for a single track.
Once you have created and modified an alignment, you ca model the rail design using the Roadway Designer command (detailed in the chapter,
Railway Design