SUR 4201L - Lab 6

 

 

 

Vertical Alignment Design

 

 

OBJECTIVE

 

The goal of this lab is to define elevations at all points along your baseline by placing vertical tangents and curves.  The existing ground profile will be created and used as a reference in the design of your proposed alignment.  In addition to designing a smooth transition into existing roads at points A and B, your alignment must attempt to meet specifications given in class to assure safety (maximum grades, k) and reduced cost (cut/fill limits).  The GEOPAK Vertical Profile Generator will be used to interactively place and modify vertical tangents and curves.  This process will result in a ‘proposed profile’, completing the 3-dimensional design of your baseline.

 

STEPS

 

Create a new road3.dgn file based on the class seed file (sur4201seed.dgn).

Also place the topo.tin file created in lab # 5, j1oXX.inp (where XX is your initials) & job1.gpk file as created in lab # 4 in the same folder.

 

First we must create the existing ground profile:

 

  1. Utilities Menu under Microstation
  2. Key-in

 

 

  1. Click on the Browse Key-in Button
  2. Select  gpktools and groundprofiles
  3. Click on the Enter button
  4. Enter a name for the output existing ground profile ("ground").
  5. Enter your Job Number. (i.e. - 1)
  6. Enter your operator code. (your initials)
  7. Click Select to enter the name of your proposed horizontal alignment chain.
  8. Enter an Offset of 0.
  9. Enter the beginning and ending station of your chain. (A quick way to do this is to delete the current station values and GEOPAK should automatically populate them based on your selected chain).
  10. Enter an Increment of 100.
  11. Enter your TIN file (topo.tin) by using the file button beside it.
  12. Apply
  13. Click OK to accept the Ground Profile Input File.
  14. Do you want to store profile? Yes
  15. Would you like to delete the 3D profile string? Yes
  16. Close the Ground Profile window.

 

Now use D&C Manager to display the profile.

 

  1. Applications
  2. GEOPAK ROAD
  3. D&C Manager
  4. Drafting standards 
  5. Metric (XX+XX Stationing)
  6. PROF Profiles LV-30's
  7. Draw Plan & Profile
  8. Enter your Job Number by using the select button.
  9. Check the labels (VPI, Horizontal Axis, Vertical Axis, V.C. Parameters & Grade Labels).
  10. Enter a label scale of 200.
  11. Click on the profile you want to draw (i.e. "ground").
  12. Enter a horizontal scale of 10 and vertical scale of 1
  13. Enter your beginning and ending station (A quick way to do this is to delete the current station values and GEOPAK should automatically populate them based on your selected chain).
  14. Leave Strip Grade Increment blank.
  15. Enter a DP Station of 10+00
  16. Enter a DP Elevation of 0
  17. Enter DP X of 1000 and DP Y of 5000.
  18. PGL Chain - Use the select button to select the chain (i.e. route)
  19. Click on the Draw Cell at XY button (the Horizontal and Vertical Axes are drawn in green, with origin coordinates 1000, 5000)
  20. OK

 

Close the D&C manager.

Use the "Fit View" button to get the ground profile in view.

 

For your Vertical Alignment Design

Attempt to meet the following criteria:

  • "Balanced" cut and fill (visual balance)
  • 3% grade maximum on vertical tangents
  • k-value >250

 

To start with your Proposed Vertical Layout

 

  1. Applications
  2. GEOPAK ROAD
  3. Geometry
  4. Layout Profiles (VPI Based)
  5. Enter Job Number. (i.e. - 1)
  6. Enter your Operator Code. (ur initials)
  7. PGL Chain - Use the select button to select your chain. (i.e. route)
  8. Set the horizontal scale to 10 and the vertical scale to 1.
  9. Set the reference station to the station where your road starts (i.e. 10+00).
  10. Set the reference elevation to 0.
  11. Enter X of 1000 and Y of 5000. (Note these coordinates must always match those used for the Ground Profile above.  This will position your new alignment over the existing ground profile so it can be used as a visual reference.)
  12. OK

 

Use the Profile Generator to select the position of your road in relation to the existing ground profile. The first task is to pick the vertical points of intersection (VPI’s).  Each VPI will be defined by a station and elevation value.  These can be typed in or "dynamically" chosen using the mouse.

 

  1. Type 10+00 in Station and press TAB
  2. Notice the station changed from OFF to LCK. This locks the beginning point to exactly 10+00.
  3. Enter 100.00 for the elevation and hit TAB.
  4. Insert After. This means we want to insert a new VPI after the currently selected one.
  5. Dynamic. (Instead of typing the station and elevation of the 2nd VPI you will choose it using the mouse)
  6. Continue to click Insert After & then Dynamic to define additional VPI’s until you reach the end of your route.
  7. When defining the last vertical tangent, use the snap mode to snap to the end point of the existing ground profile.
  8. The vertical curves are defined by design speed. Cycle through VPI’s. You may need to increase or decrease the design speed in order to meet the k-value requirement i.e. to keep k>250 and try to get the minimum possible speed range.
  9. To adjust the K-value, use the dynamic button to change the VPI position.
  10. Cycle through VPI’s one more time to make sure each has a design speed, L, and k-value.
  11. Make sure that the BK Grade is less than 3
  12. File
  13. Save
  14. Type in the name of your proposed vertical profile ("proposed").
  15. OK
  16. Exit the Profile Generator. If prompted to save the profile, hit NO as we already have saved it.

 

 

Your proposed vertical alignment is now stored in your GPK file and can be accessed through the D&C Manager. Plot your new alignment directly on top of the ground profile.

 

  1. Applications
  2. GEOPAK ROAD
  3. Design & Computation Manager
  4. PROF Profiles LV-30's
  5. Draw Plan & Profile
  6. Enter your Job Number. (i.e. – 1)
  7. Set the label scale to 400.
  8. Click on the profile you want to draw (i.e. "proposed").
  9. Enter a horizontal scale of 10 and vertical scale of 1
  10. Enter your beginning and ending station. (A quick way to do this is to delete the current station values and GEOPAK should automatically populate them based on your selected chain)
  11. Leave Strip Grade Increment blank. 
  12. Enter a DP Station of 10+00
  13. Enter a DP Elevation of 0
  14. Enter DP X of 1000 and DP Y of 5000. This will place your proposed profile directly over the ground profile.
  15. Click on the Identify Cell button
  16. Click anywhere on the cell (green axes). This selects the cell. (red color)
  17. Accept the selection by clicking on the cell again.
  18. OK
  19. Exit the D&C Manager.

 

You now have a complete vertical alignment.

 

When finished, close MicroStation and back up your files (road3.dgn, job1.gpk & j1oXX.inp where XX is your initials).

 

To edit an existing vertical profiles follow these steps:

 

  1. Applications
  2. GEOPAK ROAD
  3. Geometry
  4. Layout Profiles (VPI Based)
  5. Enter Job Number. (i.e. - 1)
  6. Enter your Operator Code. (your initials)
  7. PGL Chain - Use the select button to select your chain. (i.e. route)
  8. Set the horizontal scale to 10 and the vertical scale to 1.
  9. Set the reference station to the station where your road starts (i.e. 10+00).
  10. Set the reference elevation to 0.
  11. Enter X of 1000 and Y of 5000. (Note these coordinates must always match those used for the Ground Profile above.  This will position your new alignment over the existing ground profile so it can be used as a visual reference.)
  12. OK
  13.  

 

This opens the familiar Profile Generator.  Instead of starting a new profile load your existing design.

 

  1. File
  2. Load
  3. Select your proposed profile.
  4. OK
  5. Now you can navigate through your route, delete and insert VPI’s, etc...

 

 

 

 

 

 

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 Last updated: 4/27/2005