3D Feature lines- Change grades

[jenniferchavez]

I am trying to grade a subdivision. I have created a surface from my road and I am now using feature lines created from the assembly along the right of way. I am offseting the feature lines 20' at a 2% slope for the drive ways. It will not keep the grade. In some places it works, in other places it ignores it. I have tried just creating feature lines going at a 2% slope for 20' and it will change the grade to something like 23% once I add it to the surface. How can it just change the grade on a feature line by itself?????

This is a simple site that has taken me 8 hours instead of 3. UGH!!!!!!!!!!

[brian.hailey933139]

The first thing that comes to mind is Sites. Do you have alignments, parcels, other feature lines, or grading in the same site as these feature lines?

[rpwband]

This happen to me also. It looked like the straight segments had the right elevation but if it had an arc in it, it didn't work. I ended up offsetting the feature line then using the edit feature line command and lowering the elevation of the feature line by the difference and it worked every time. Sorry if my terminology is off, I'm at home away from C3d for a couple of days.

[grice6802]

I am trying to grade a subdivision. I have created a surface from my road and I am now using feature lines created from the assembly along the right of way. I am offseting the feature lines 20' at a 2% slope for the drive ways. It will not keep the grade. In some places it works, in other places it ignores it. I have tried just creating feature lines going at a 2% slope for 20' and it will change the grade to something like 23% once I add it to the surface. How can it just change the grade on a feature line by itself?????

This is a simple site that has taken me 8 hours instead of 3. UGH!!!!!!!!!!

get an answer?

I would have this as part of my assembly!

if there is some reason you don't won't do do this, try create a curb with a realitive elevation change instead of by slope. more reliable

i would first look at the elevation editor to see if there is reason for this working some places and not others.

In this case of creating a feature from a corridor you can dynamically link it back to the corridor. then try grading objects to keep the first twenty feet dynamic.
for this reason

[nguyenhoangquan]

Another reason can be settings of the surface build (definition tag in surface properties). When you add feature lines into a surface, whenever a crossing or overlapping of feature lines occur - a solution is needed. 4 options are available:
1. Will not alow the added feature lines/ breaklines
2. Use elevation of lastly added feature line(s)
3. Use elevations of first added feature line(s)
4. Use average elevations of feature lines at crossing

In your case, it can be option 3 or option 4 was selected that causes changes in elevations/grades of your feature lines. Also, within one SITE there will be only 1 elevation at one location thus there will be mutual influence between feature lines crossing each other.

[Chud]

Another reason can be settings of the surface build (definition tag in surface properties). When you add feature lines into a surface, whenever a crossing or overlapping of feature lines occur - a solution is needed. 4 options are available:
1. Will not alow the added feature lines/ breaklines
2. Use elevation of lastly added feature line(s)
3. Use elevations of first added feature line(s)
4. Use average elevations of feature lines at crossing

In your case, it can be option 3 or option 4 was selected that causes changes in elevations/grades of your feature lines. Also, within one SITE there will be only 1 elevation at one location thus there will be mutual influence between feature lines crossing each other.

What style is this definition tag under? Is there a way to disable this need to solve crossing feature lines?

[mjfarrell]

I would stop using the stepped offset for this function,
and either use an assembly for the driveways added vie the section editor
or creating a Grading Criteria and grading the driveways in that manner.

[mjfarrell]

What style is this definition tag under? Is there a way to disable this need to solve crossing feature lines?

Yes in the Surface settings (Build) tab one can allow crossing breakline or in this instance NOT Allow them. Then you will get an error when they occur, and you can resolve them if needed.