OpenROADS Vertical Geometry Tools

What vertical geometry tools should I use to create a proposed profile that is 2 inches above the existing terrain and has 50' transitions back to existing elevation at both ends?  I was able to create the 2" build up no problem using the "Profile from Surface" tool , but cannot figure out how to create the 50' transitions.  In SS2 I would place calculation lines on my profile at the tie ins and then offset them in 50' and snap lines between that calc line and the 2" build up, but the new profile viewer does not allow you place calculation lines so I can't locate the exact station to tie in. I'd like something to snap to versus typing in the station so there isn't a rounding issue.

Parents
  • Hi David:  Here is a video showing the use of Civil Accudraw in the workflow you describe.  As you have found, you can indeed use construction lines and snaps to solve the problem.  I encourage you to explore Civil Accudraw in plan and profile workflows because it will solve many problems more efficiently than other workflows.  In your specific example, Civil Accudraw is a technically better solution because snap rules are sometimes unreliable.  If you snap to a vertex that is not the start point or end point then the snap rules may not update as expected if changes are made to the design.

    In this video you will see:

    1. I created an offset profile from existing ground.  I used a 1 ft offset instead of 2inches for better clarity in the video. I made a blunder here when first starting because I set the start and end station incorrectly, so I changed these in properties.
    2. Then I used civil accudraw in profile with the Profile Line Between Points command to transition to existing ground.  Geometrically, for my data, this is not a very good transition.  But it shows the use of civil accudraw to lock the offset from a surface.  You will also notice that I used a station keyin rather than a snap for reasons noted above.
    3. Then I repeated the process using curve between points command.  Same thing as line between points using civil accudraw.
    4. Also keep in mind the following not shown in the video.
      1. This workflow is valid for any of the profile commands. Civil Accudraw simply assists in defining points.  So whichever command provides the best geometric transition can be used.
      2. In the video I used keyed in station values, but you can also snap in plan view (such as beginning of the edge of pavement, which locks the station and rules it to whatever you snapped.
      3. IN the video I used the original ground surface with zero and 1.0 offsets using accudraw.  You could also use zero offset from the two different lines which is perhaps a better rule to preserve for design intent

    Robert Garrett
    Senior Product Engineer
    Bentley Systems Inc.



  • Thanks for the video. I found it to be very helpful. In your note 4 (#2), you mention about snapping to the edge of road in the plan view and have it recognize that station on the profile view. That's really all I'm trying to do and that's what I was having trouble with. Whenever I would snap to an element in the plan view it would place my line at 0 elevation.
  • Unknown said:
    Whenever I would snap to an element in the plan view it would place my line at 0 elevation.

    This is the reason I've had to draw vertical lines at the relevant stations, and then do an intersection at the existing profile. But if there's a better way to handle this, I'm all ears.

  • Yep, sure.  Here is another video.  I focused on just the creation of rules to a plan element.  So here what you see is:

    • I am looking at the end of the alignment this time and I ignored the 2inches offset discussed previously.
    • Profile Line Between Points Command but works with any command.
    • Use civil Accudraw in profile
    • When prompted for the first point in the line, I Tentative snap to the end of the edge of pavement in plan. This locks the station and creates a rule to the plan element.
    • Then if the edge of pavement position changes then the profile updates.

     

    Robert Garrett
    Senior Product Engineer
    Bentley Systems Inc.



    Answer Verified By: David Neidig 

  • That video was perfect and I see the design intent in doing that. Thanks Robert.
  • What did you do at about 30 seconds in? Leading up to that, I see that you did a keypoint snap at the end of the edge of pavement, and then you probably hit Enter to lock that station (as I see the lock there), and then you clicked into the profile. Then I can't tell what you did to snap to the existing profile.
  • Never mind. My failure was that I didn't actually watch your first video (nor, to my shame, properly read your writeup). I understand now that instead of using Z or dZ, you do profile offset, which I understand to be an offset from the active profile (in this case, the existing profile)--or perhaps any profile of the user's choice. And I didn't realize that you were pointing that out in the second video too.

    Thanks, Robert.

Reply Children
No Data