I found a similar forum post that discusses my question, but I was wondering if Openroads may have updated/users have found a solution since.
communities.bentley.com/.../640707
I had created a ditch terrain, and I was wondering if there was a way to export this terrain into the OpenRoads ditch library. The ditches provided by the conduit catalog are straight between nodes, which may not be representative of a real ditch with variable slope.
If this is not possible, I was also wondering if there was a way to create ditch nodes that would conform to a chosen terrain. I know that Irregular Channels and Cross Sections are an option, but having to create many multiple cross sections throughout the system would be much time consuming.
Thanks,
You are correct, HEC-22 does not accommodate vertical breaks in conduits. Any conduit (open or closed) is treated hydraulically as a straight slope.
Unless you are working with truly irregular ditches, I am of the opinion that a regular V or Trap shape is sufficiently accurate. in a hydraulic sense, that extracting from the terrain doesn't really add much to the analysis. You may disagree, which is fine.
What I do is create the conduit from start to end and then compare to the ditch profile from the roadway model. How? Insert sufficient number of bends until the path of the ditch matches (within reason) the path of the ditch as defined in the roadway model. Why? Because this makes it easy to see if and where there are any profile breaks in the ditch. Then use insert node (dummy feature definition) to break the ditch into multiple conduits such that each conduit has a single slope which suitably matches the physical ditch profile. The result is multiple adjacent ditches.
Could you use channels instead of conduits? Yes, and I think (maybe?) that an irregular channel can (maybe?) extract from the terrain model. However, besides the potential for lots of sections being needed, a channel can only end at an outfall, thus no channels can exist in the middle of a network. You could not have a channel which starts at a certain location and then drops into an inlet, for example. You could employ some trickeration, I suppose, and treat the channel as an isolated network and manufacture some sort of outfall that mimics the characteristics of the inlet and.....AiYiYi.
Robert Garrett Senior Consultant
www.envisioncad.com
why would you want to conform to a terrain?
if you're purpose is to analyze the channel then making a general approximate is fine for calculation purposes. if this is a designed ditch/stream then it should be uniform or nearly uniform for ease of construction. Remember a basic rule of engineering if its complicated then break it down to simple pieces.
Thomas W said:I was also wondering if there was a way to create ditch nodes that would conform to a chosen terrain.
ok if you absolutely have to then yes create a horizontal&vertical alignment along the center of the ditch or if its a created terrain pick a feature in the center.
Next use the "Place Nodes" command and set an interval distance.
You could try using the extract from graphics but i doubt that would be any better since you'd have to have some lines doing the same as alignments or features.
if thats not sufficient then the best bet is to work on a Macro or other custom program to do what you want.
The end result hydraulically is the same as a straight line from start to end unless you have horizontal bends which I'm not even sure ORD can handle but hydraulic toolbox can provide guidance.