Within a couple of releases of Civil 3D, we have been able to generate superelevation data semi-automatically. However, there are times that we need to manually input data, whether we are implementing known values from a previous design or just want to clean up some of the results we are given. In either case, a good understanding of our options and capabilities. Here we will discuss how to manually input stationing, parameters, and critical data along an alignment that may have errant results or to simply start from scratch.
Depending on the complexity or length of your alignment, you may find it helpful to have the panorama of the alignment geometry handy to keep track of the curve in which you are working. This comes up as an issue when you enter stationing that overlaps other curves (overlaps) or when you enter data on an incorrect curve.
For the sample data, I have an alignment composed of a tangent-curve-tangent-curve, stationed left-to-right. When calculating the superelevation using the wizard, I receive data that has my stationing for the two curves overlapping due to the length of the tangent between them (300’).
I could choose to resolve the overlap automatically, or I could ignore it and manually make changes. That’s pretty helpful in design, but what if I want to mimic a set of plans that has this data for me and I want to simply input the design into Civil 3D?
What I will do is wipe the slate clean by clicking on the button towards the end of the icons at the top of the Superelevation Tabular Editor panorama labeled ‘Clear all Superelevation Data’
This will allow me to define the extents of crowns, transitions, and superelevation locations. Focusing on the first curve, Curve.1, right-clicking on the curve name gives me the option to add a station, which takes me to the drawing window. Here, you click a location or type a station value, then are returned to the editor with a Manual Entry.
Now, based on my design, I will define what that entry represents. This one will represent the location where the normal crown design ends. To define this, right-click on Manual Station -> Assign Critical Station -> End Normal Crown. This resides in the ‘Transition In Region’, heading into the curve. Now, I will repeat by right-clicking End Normal Crown and adding another station.
Now, I will choose a station where I want the full superelevation shaping to begin, which defines the end of the transition. Right-click on End Normal Crown -> Add Station. Then, right-click on Manual Station -> Assign Critical Station -> Begin Full Super to define the superelevation range. This completes the ‘Transition In Region’.
You can now right-click on any of the entries and Add Station, pick or type a station. Since we want to define the Transition Out Region, I will choose, from the design, the station towards the end of the curve that begins the transition back to a normal crown. This one should be assigned End Full Super and is automatically sorted into the Transition Out Region grouping in the list. The last one to add is Begin Normal Crown and a basic (keep that in mind) setup of my transitions is complete.
Of course, from looking at the many options of critical stations that can be assigned, more can be done and delineated within this editor panorama.
Finally, if the data you need exists in a CSV file, you can import the data to more quickly define the needed paramaters. The button for this is found along the icons at the top of the editor.
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