Designing roads using string editing tools

In this chapter, you will learn how to create a road design by using simple string editing tools available in the Core Module.

Task: Design a road using CURVE END

In this task, you will learn how to use the function CURVE END to create a road design containing a simple horizontal curve with transition curves on either side.

1. Click Reset graphics.
2. Open pit&dump.str in Graphics.
3. Open pit_dump_road_centreline.str in Graphics.
4. Zoom out to view the data as shown.



5. In the Layers pane, double-click main graphics layer to set it as the default layer.



6. Click the design string button on the Status bar.
7. Enter the information as shown, and click Apply.



Design string number 4 will be used for the road centreline.

8. Choose Create > Points > By angle.
9. Click Point 1 and then Point 2, as shown.



10. Enter the information as shown, and click Apply.



This creates the start point for the new road, which is at the same coordinates as the point near the second point selected.The point is created in string 4.

11. Click the same two points again.
12. Enter the information as shown, and click Apply.



This creates the second point of the road centreline, as shown.



13. Press ESC.
14. Choose Create > Curve at segment end.
15. Click Point 1 and then Point 2, as shown.



16. Enter the information as shown, and click Calculate.



17. After the transition lengths are calculated (as shown), click Apply.



18. Press ESC.

19. Zoom into the view as shown.

    

20. Choose Display > Point > Markers.
21. Enter the information as shown, and click Apply.



Note: Points have been created every 30 metres along the arc length to approximate the curve.



22. Choose Display > Point > Attributes.
23. Enter the information as shown, and click Apply.



Note: The points where the transition curve ends, and the simple curve begins have the description "End transition curve".



24. Choose Inquire > Bearing and distance between 2 points.
25. Click Point 1 and then click Point 2, as shown.



26. Press ESC.

The bearing from Point 1 to Point 2 is displayed in the message window, as shown.



Next, the road centreline will be extended at this bearing.

27. Choose Create > Points > By bearing.
28. Click the end of the curve (Point 2 in the previous image).
29. Enter the information as shown, and click Apply.



30. Press ESC.

The road centreline is extended horizontally 200 metres at the bearing of 331 degrees, 49 minutes, 10 seconds, as shown.



The centreline design is complete. The next step is to create the road outline.

31. Click the design string button on the Status bar.
32. Enter the information as shown, and click Apply.



The design string number of 9 will be used for the road outline.

33. Choose Design > Underground tools > Room & pillar from centrelines.
34. Enter the information as shown, and click Apply.



The road outline is created, as shown.



Note: The function MAKE PILLARS is used to create the road outline in this example.

35. Click Save .
36. Enter the information as shown, and click Apply.

Note: To see all the steps performed in this section, run 1a_curve_end.tcl. You need to click Apply on any forms presented.

Task: Design a road using CURVE TANGENT

In this task, you will learn how to use the function CURVE TANGENT to create a road design from a centreline string that contains an inflection point.

1. Click Reset graphics.
2. Open pit&dump.str in Graphics.
3. Open pit_dump_road_centreline.str in Graphics.

Zoom into the view as shown.



4. Choose Display > Point > Numbers.
5. Enter the information as shown, and click Apply.



The point numbers are displayed, as shown.



Note: It is not necessary to display the point numbers. This is done in this example to identify the points to select.

6. From the mode selector, choose Insert point mode.

   

   Note: The insert mode will result in points inserted within the centreline string when the curve is created.

7. Choose Create > Curve from tangents.
8. Click Point 1 and then Point 2.

   Note: The line connecting points 1 and 2 define the first tangent.

9. Click Point 2 (again) and then Point 3.

   Note: The line connecting points 2 and 3 define the second tangent.

10. Enter the information as shown, and click Apply.



Note: In this example, a simple curve is created because you have not selected Use transition curve.

11. Press ESC.
12. Choose Display > Hide point > Attributes.
13. Enter the information as shown, and click Apply.



You should now see the curve as shown, created between the two tangents.



14. Click the design string button on the status bar.
15. Enter the information as shown, and click Apply.



The design string number of 9 will be used for the road outline.

16. Choose Design > Underground tools > Room & pillar from centrelines.
17. Enter the information as shown, and click Apply.



The road outline is created, as shown.



Note: The function MAKE PILLARS is used to create the road outline in this example, as the function is a part of the Core Module.

18. Click Save .
19. Enter the information as shown, and click Apply.

Note: To see all the steps performed in this section, run 1b_curve_tangent.tcl. You need to click Apply on any forms presented.

Task: Design a road at a Constant Gradient Along Contours

In this task, you will create an access road with a maximum gradient of 5%.  The road design will be based on a string file of topography contours.

1. Click Reset graphics.
2. Open pit&dump.str in Graphics.
3. Open access_start&end.str in Graphics.
4. Choose Display > Point > Attributes.
5. Enter the information as shown, and click Apply.



In this example, the goal is to create the shortest, straightest road possible between these two points, while ensuring that the maximum gradient is not more than 5%.



6. In the Layers pane, double-click main graphics layer to set it as the default layer.



7. Click the Design string button on the Status bar.
8. Enter the information as shown, and click Apply.



The design string number 2 will be used for the road centreline.

9. Click the design grade button on the Status bar.
10. Enter the information as shown, and click Apply.



Note: In this example, you will not use the actual design gradient value (set to zero in the previous form) to create points. You will digitise points, and want to see the gradient between any two points expressed as a percentage. By setting the units to percentage, the gradient between the digitised points will be displayed as a value in percent in the Status bar.

11. Choose Create > Digitise > New point .
12. Click the Snap mode drop-down, and select Point.



13. Click the Access road start point as shown.



14. Right-click in Graphics, and select Line.



15. Move the cursor along the contour as shown.





Note: As you move the cursor along the contour line, the gradient (expressed as a percentage in the status bar) will change. Remember that the goal is to create a road with a centreline at a maximum gradient of 5%. Since we are designing from the uppermost point down, the gradient will be -5%.

16. Click on the contour line near Point 2 when the percentage value displayed in the Status bar is approximately -5%, as shown.



Note: There will be two or more locations along a contour where the gradient will be the same. In this example, the points are selected based on the desire to create a road that is as straight as possible.

17. Click on the contour line near Point 3, when the gradient is approximately -5%, as shown.



18. Click on the next contour line near Point 4, when the gradient is approximately -5%, as shown.



19. Click on the next contour line near Point 5, when the gradient is approximately -5% as shown.



20. Click on the next contour line near Point 6, when the gradient is approximately -5% as shown.



21. Click on the next contour line near Point 7, when the gradient is approximately -5% as shown.



22. Click the Access road end point, as shown.



23. Press ESC.

24. Click the design string button on the Status bar.
25. Enter the information as shown, and click Apply.



The design string number of 9 will be used for the road outline.

26. Choose Design > Underground tools > Room & pillar from centrelines.
27. Enter the information as shown, and click Apply.



The road outline is created, as shown.



28. Click Save .
29. Enter the information as shown, and click Apply.

Note: To see all the steps performed in this section, run 1c_access_road.tcl. You need to click Apply on any forms presented.

Task: Create a variable width road outline

In this task, you will learn how to create a road outline of variable width from several centreline strings.

1. Click Reset graphics.
2. Open pit&dump.str in Graphics.
3. Open all_centrelines.str in Graphics.
4. In the Layers pane, click the eye icon to hide pit&dump.str.



5. Choose Display > Strings > With string numbers.
6. Enter the information as shown, and click Apply.



The road centreline strings are displayed.



7. Choose File tools > String maths.
8. Enter the information as shown, and click Apply.



Note: The D1 field is set to the desired road width for each string or string range.

9. If prompted, click Apply to overwrite the file.





10. Open all_centrelines.str in Graphics.

    Note: The output of the STR MATHS function is written to the file on disk. To have the information available for MAKE PILLARS, it must be re-opened in Graphics.

11. Click the design string button on the status bar.
12. Enter the information as shown, and click Apply.



The design string number 9 will be used for the road outline.

13. Choose Design > Underground tools > Room & pillar from centrelines.
14. Enter the information as shown, and then click Apply.



The road outline for all centrelines is created at the width specified in the D1 field.



15. Click Save .
16. Enter the information as shown, and click Apply.

Note: To see all the steps performed in this section, run 1d_variable_width_outline.tcl. You will need to click Apply on any forms presented.