Creating assemblies - full road cross section

[Anonymous]

I am trying to model a road cross section. I have profiles for the road cl and ditch inverts on either side and i would like to be able to make an assembly that incorpates this design info. Right now i have the road surface using the generic link width and slope. Then i used link slope to surface. (had to built design ditch surface) but this got me to the bottom of the ditch (toe). The ditch is 1m wide and daylights into the current ground at a 3:1. How do i complete the model to incorporate the ditch width and that backslope?

I feel there is better way i am over looking, as this seems pretty basic/standard. Any ideas would be helpful thanks

[tcorey]

Instead of creating a special surface for the ditch and using a daylighting subassembly to target it, create a feature line or 3d poly line that represents the ditch, and then use LinkWidthandSlope to target that for both hz and vrt. Now you can attach another LinkWidthandSlope for the bottom of ditch, another for backs lope of ditch and then attach a daylighting subassembly.

[Lisa_Pohlmeyer]

Or, you could create a profile for the ditch in the profile view of the roadway, and use it for the vert target.  Lots of options with the LinkWidthSlope or LinkSlopeElevation. I've attached a couple of images with each. If your ditch isn't a consistant offset, you could use a polyline for the horiz target.

[Anonymous]

Thank you both for your replies

The problem is, the ditch alignment (horizontal target) is a function of the side slope, and varies because of changing road cl and ditch invert grades. I finished the assembly by adding the subassemblys to get ditch width and backslope, i didn't realize you could add subassemblys after targeting a surface. For the toe of the ditch, targeting a surface is ideal because the model determines the toe location on its own. I made the surface just guessing where the toe would be, and made a surface off a 3dpoly wide enough(feature line offsets) so the side slope could daylight. Making the surface is a bit time consuming with all the ditch grades.

I have the profiles drawn. Ideally i would like to just target them, but not sure how to do that with out any horizontal alignment

[Lisa_Pohlmeyer · Accepted solution]

In the scenario I stated earlier, the roadway would have multiple profiles. For example:
EG CL
FG CL
Ditch LT
Ditch RT, etc.
You can then use the ditch profile as one of your vertical targets for LinkSlopeElevation and/or some of the other generic links. They vary as to what can be used as a target. Some will allow a variable slope, some allow you to set a fixed slope and use a vertical target for the elevation. I typically do this as our foreslope is 4:1, I then use the ditch profile as the target. When you view the resulting featureline, it's horiz placement will vary depending on the profile elevation.

[Anonymous]

Ok thanks, that sounds good. I'll have a closer look at this when i have time later this week and get back to you.