Limits of Grading

[Vasily_BC]

Hi,

I'm trying to do grading for a powerhouse with two surfaces. One is overburden level and another is rock.

Grading of excavation to rock surface from relatively simple geometry of PH is going pretty straight forward.

However, grading to overburden is going not so smooth. The reason I suppose in number of vertices along feature line and difference of elevation.

So I'm asking, is there a reasonable limit of vertices for feature line?

As example, my original rock surface daylight feature line has 170 vertices.

I made a copy and weeded it to 30 and it still crushes my system...

Thanks

[Neilw_05]

It's not clear to me what you are doing but it seems you are creating a grading from a featureline representing the powerhouse pad or building to a rock surface, then you are applying another grading from the first that targets the over-burden surface. In any case C3D grading processing times quickly become intolerable when there are many elevation points on the parent featureline. I can't say how many points is too many but 170 is definitely going to cause problems in my experience.

The crashing could be due to drawing corruption, corrupt gradings, surface anomalies or insufficient memory (you need at least 8GB ram and 64 bit OS) to name a few.

[Vasily_BC]

Thanks for respond,

You right, I'm doing grading from underground level of PH to rock and than overburden surface.

I guess I just need to do try and error with number of vertices on a feature line.

More I weed- less precision will be in calculation.

[rachelc11]

A feature line with many vertices is bad. Grading a feature line  in a concave direction with many vertices will crash my computer every time. Not a good idea. I sometimes guess where the daylight line would be, draw that and give it the surface elevations, and then grade back the other way. Hope that kind of makes sense!

[Joe-Bouza]

Why does the PH have so many verts? does the pad have many jogs in it? if so, you might  try a curbed offset a x% then filet out the jogs ( in a sensible manner, add an infill and project from the normalized line

[Neilw_05]

Joe, it's not the pad that is causing the problem. It's the daylight line where it hits the Rock surface. He is applying a grading to that daylight line and projecting it to the Over burden surface.

[sboon]

I've found that the number of vertices isn't usually a problem but featurelines with many bends can certainly led to problems.  When the grading calculation has to deal with many overlapping projections it's much more likely to crash.

Steve
Please use the Accept as Solution or Kudo buttons when appropriate

[Joe-Bouza]

Ah, Neil straightened me out.

I would daylight to rock>> temporarily move the daylight FL to a new site, edit/filet/smoothe this FL to an acceptable configuration>> get elevation from rock surface>> move back to grading site>> infill>> daylight to the next surface

[Vasily_BC]

It's exactly what I did. And I wonder how far you may want to weed daylight to make it work?
Yes, PH floor feature line is not the main reason why Civil 3D crushes I guess. It's different elevations of daylight.

Thanks for reply!

[Vasily_BC]

Sometimes I have a feeling that in such cases corridor may work much better...

[Joe-Bouza]

Well. if a constant slope isn't imperative then cleaning up the daylight line should be a detriment to design.?

[Neilw_05]

A corridor might handle it better. Be aware that corridors don't handle sharp corners and you'll need to run a small frequency interval to get a tight solution.