Power Civil v8i
I need some ideas on how to model a road with walls in specific locations. I have attached a screen capture showing the scenario. I first tried creating the walls as seperate objects by draping a parent element onto the road object and adding slope elements with benching to the draped object to create the wall. The problem with this approach is the wall is tying in to the 2:1 road slopes rather than existing terrain since the road has to be processed first.
My second approach is to set up the comp section for the road to look for the wall graphics and apply the wall using slope elements. The problem with this approach is the slope element in comp section does not provide benching options. Also, with this approach I have to predetermine the wall locations, yet I need to see where the 2:1 slopes will daylight in order to locate the walls. Thirdly, by manually placing the wall graphics I have to manually edit the graphics if the road alignment changes. In this case I am trying to find an optimum route so the alignment must be flexible. Thus I need the graphics to be tied to the alignment baseline somehow. I tried using comp section to create an orphan wall element using the baseline alignment and profile with station range and then adding parallel wall elements to that orphan element, but this approach has the same issue as my first approach presented above with regard to the road slopes.
A few other ideas I've had are;
Use dynamic slopes on the road to adjust the 2:1 slopes at the walls so that the walls will find original ground beyond the road shoulder. The problem here is the road slope transitions must vary when the alignment changes.
Use slope elements for the road daylighting rather than slope parameters and clip/edit the daylight elements in the location of the walls. This approach is not dynamic to changes in the road alignment or profile.
Perhaps Power Civil is not up to this task. Would Roadway Designer be able to handle this?
Hi Neil,
tough question :-)
I'm going to follow with your first thought for now... that appears to be the best option (I think... without actually having your data to try some things myself).
You say "The problem with this approach is the wall is tying in to the 2:1 road slopes rather than existing terrain since the road has to be processed first.". Do I assume you are creating the Slope Element to the Model? There is the option of creating the slope element to an Object... in this case Existing Ground.
Would that work?
Hopefully this graphic will clarify the slope problem. If the road is processed first in FIFO, the wall will see the 2:1 slopes in heavy cut situations since the slope will extend well beyond the edge of roadway and wall. If I put the wall first in FIFO, the road object will wipe it out of the TIN since the shoulder extends beyond the wall. I don't see how using a slope element for daylighting will help in this case. In my mind I think using a comp section with an orphan parent element from a range of the Chain and profile would be ideal if it weren't for this slope issue.
I'd post the GSF but it is far too large, mainly because of the existing ground object.
Neil Wilson (aka Neilw)
Power Civil v8i 08.11.07.245
AutoCAD Civil 3D 2018
That image clarifies a LOT. I misunderstood the original problem.
What I am seeing is that the wall/benching is created correctly BUT the finished model is not correct due to the points you have made... correct?
Have you tried adding all the Wall Objects elements to the Road Object?
Make the Road Object active.
1) Object>Edit
2) Add Elements to Object
3) Select all of the Wall elements.
4) Click Apply...
Does this improve the final result?
Depending on how things look after this, you may want to remove the Wall Object from the Model (Model>Edit>FIFO>Remove Object).
HTHs (fingers crossed).
I did try that earlier on. The problem is the road shoulder extends beyond the wall, so if I add the wall elements to the road, the shoulder breakline mixes with the wall breaklines and makes a mess. Also, if I include the wall elements in the road object, they no longer react to changes in the road profile since they would have circular associations.
Still thinking
Hmm...
While this wont solve the cyclic dependancy issue, a partical delete of the shoulder (Modeler>Elements>Modify) would remove the traingulation conflict that you mention.
Still thinking also...