question about Axis of Rotation (AOR)

[joantopo]

Hi.

We have a new project and we must use the AOR.

We are using 4 LaneSuperElevationAOR subassemblies with the property: Potential Pivot= Yes and the properly Use SuperElevation for each case.

About the alignment, in the "Calculate SuperElevation" dialog box, this is our settings:

-Undivided Crowned.

- Pivot Method: Inside of curve.

This project is a 2+1 road:

https://en.wikipedia.org/wiki/2%2B1_road

But there are 5 pivot methods:

-Center BaseLine.

-Inside of curve.

-outside of curve.

-Left side.

-Right side.

But the "Inside of curve" method is only for curves I think and we need also a method for the straight lines at the same time.

Perhaps, we need this pivot method:  Inside of the curve AND Rigth side.

"The right side" would be only applied in the portions where there are lines in the alignment.

Any ideas?

In addition, I would like to know where I could get more info about AOR concept in Civil 3D.

Thanks in advance.

[tcorey]

The "straight lines" are super elevated as they enter and exit the curve, based on the runoff and runout values you supply. There are not separate entries for the tangents. 

[joantopo]

Hi @tcorey ;

I don´t understand the difference between the "inside of curve" and "outside of the curve":

This section station is in the middle of the start spiral previous a curve.

If I select the type: "inside of curve", the section corridor is on the red polyline.

If I select the type: "outside the curve", the section corridor is lower (under the red polyline).

But in both cases, the SuperElevation for each subassembly doesn´t change.

In addition, what happens in the tangents?

If we have a 2+1 road, in the tangents of the alignments we also need an axis of rotation different from the alignment. (in the left or in the right side).

The concept of "axis of rotation" is only for SuperElevation curves?  This concept would have to be also expanded for tangent entities of the alignment.

[joantopo]

OK, we cannot apply a AOR pivot method for tangents:

"Note:Superelevation axis of rotation calculations are performed only on stations that are in the superelevation curve group. This includes any alignment stations that are between the End Normal Shoulder/End Normal Crown and Begin Normal Shoulder/Begin Normal Crown critical stations."

http://docs.autodesk.com/CIV3D/2014/ENU/index.html?url=filesCUG/GUID-D2AE662B-DF6A-4F51-9048-EAF715F...

However, the end Normal crown and Begin Normal crown are part of the tangents.

The issue is in the start station alignment and end station alignment. (we cannot edit these superelevation critical stations--- they are internals). we cannot edit neither with API. (and we cannot apply a AOR pivot method for them).

To solve this, I must create a manual superelevation critical station in the station 0+000.0001 and another one 1mm before the end station.

And then put the properly superelevation for Outside left lane, inside left lane, inside right lane and outside right lane...

I recommend read this page:

http://docs.autodesk.com/CIV3D/2014/ENU/index.html?url=filesCUG/GUID-D2AE662B-DF6A-4F51-9048-EAF715F...