Inward Corridor Grading - Custom SA?

[jmartt]

I've got an irregular shaped site boundary on irregularly sloped ground.

I want to know how much material I can place within that shape, given an angle of repose. (2:1 sideslopes.)

What would be the best way to arrive at a maximum volume?

I wonder if I couldn't do this somehow with a corridor?

I've had a degree of success using a ridge FL and grading down or by using FLs at the edges and offseting them up, making surfaces, finding the intersections, etc etc, but I wonder if there isn't a known trick using corridors that I can't find on Google?

Thanks.

[CivilFlow]

Hi @jmartt-

Can you provide a screen clip of the area?  I have a some ideas, but want to confirm it will work for your situation.

Thanks,

[jmartt]

I would like to include much more information about what I did, but no time presently.

I didn't use a corridor, though, which is what I want to do.

[CivilFlow]

Thanks...which side of the polygon is the toe of slope of 2H:1V?

[jmartt]

All of 'em.

[jmartt]

Oh. I'm sorry; I misread that. It's the inside of that polygon. But from all of the tangents, is what I meant. I wondered if there wasn't a way to make a SA that would grade up to itself at 2:1 and form ridges at the highest intersections. Probably not.

I drew a FL on the high side of the existing ground along the boundary and grabbed surface elevations. Then offset the FL at 2:1, made a surface, and graded other FL along the other tangents up to that surface. What was nice was that there were daylight polylines, generated from the grading, that I could snap to in order to create ridges. Then I graded the ridge polylines down at 2:1, essentially tracing over the temporary surfaces I used to create the ridges. I was left with a pile that just barely fit in the shape.

[CivilFlow · Accepted solution]

No worries...I follow now, but I'm having a tough time visualizing the scale of this footprint 🙂   However, in order to get it to the point to build a corridor you need to do some initial steps.  No subassembly will behave nice for this task lol.

At first, I would treat each side of the polygon separately and create individual feature lines for each segment and then create associated Grade to Distance Grading Objects from them.  Please note, that these feature lines would need to extend beyond the PIs or corners of the polygon (maintaining the grade of the feature segments).  So my thought is to have separate grading slope reference planes that you will evaluate relative to each other to find the various slope intersections (via MINIMUMDISTANCEBETWEENSURFACES command).  You will have to do this command for each segment around the polygon (I would have separate colors for each intersection evaluation---to keep it straight as 3d polys are created).  Then you can trim / weed the vertices / and finally join the final top ridge.  This 3D poly can be converted to a feature line that could be targeted with a simple corridor link width and slope generic link Assembly. 

***edit - you may also need some additional feature line targets at the very corners up to the final top ridge for the corridor.  So you will have more than one feature line target...and may even need create regions) to separate the sharp areas.

I hop this helps.  

[jmartt]

Sure did. Your description matches what I thought was possible. I believe it's basically the same end result as what I did...Except for one thing...And this is maybe the only aspect of grading that I've come to not hate: When I graded down from my ridgelines, instead of up from a boundary to the ridgeline target, (which was, admittedly, exactly what I asked for), the grading handled corners in a more believable manner. There's only so much of a 90 degree angle that you can fill with gravel, of course.

Thanks.

[CivilFlow]

Great point! Good luck with your project.

Cheers,