Determine elevations along slope

[randcdavidson]

I need to project a surface/grading (or something of that nature) across my berm and have it intersect with the inside bank. This is better explained if you see the attached image. In the plan view you see 4 featurelines. Outside TOE, outside TOB, inside TOB then inside TOE. I need to project the outside TOE across the berm (shown in the section view) then create a new featureline where the line and inside slope of the berm intersect. Note that all the elevation shots vary as does the widths across the berm. What's the best way to do this?

[Joe-Bouza]

create the FL at the toe of the berm create a grading with auto surface checked, by distance at 0% far enought to pass the other side of the berm. Now make a volume surface of the Berm & the Grading and extract the 0 contour at the opposite side of the berm

[randcdavidson]

I tried this however it places my volume surface at 0 elevation

[fcernst]

Command: _AeccAdjacentFeatureElevsByRef

[Joe-Bouza]

Sounds like you have the same two surfaces in you volume surface. check again.

[Joe-Bouza]

Hi Fred, I may be missing something; although that will give the correct elevation how does it give the correct location?

[fcernst]

Oh right, didn't read that carefully.

He could create a corridor with a short flat width link and attach a link to surface with a horizontal daylight slope and extract the feature line.

[troma]

I would've done a grading, same as Joe. But then just explode it; the target featureline is the location we're looking for, correct? No need for a grading surface or volume surface.

[Neilw_05]

Isn't there a new feature (2013?) that automatically creates a dynamic boundary between 2 surfaces? I don't know what the command is, nor could I find it in help.

[fcernst]

A Corridor is much more versatile. He can create sections for his team to look at, do a quick berm volume table by station, and show quickly the area with hatching in plan view. 

[randcdavidson]

Troma. How will this find the point where the grading intersects the inside berm? That is the area where I need the new 3dpolyline or featureline to be. I need that to get an area

[randcdavidson]

The "volume" surface is created out of the EG and new surface from the grading. As you see once created it gets placed below the EG. No way to extract the contour at the correct elevation

[Joe-Bouza]

The 0 elevation contour of the volume surface would be at the location where EG & the Grading intersect (where the volume is 0. This only locates the point alont the back slope, then you would turn to FL and assign elevation from the berm surface

[randcdavidson]

Joe. what I wound up doing is an infill on the inside bank between the Inside TOE and Inside TOB. I then created a surface I called "face" out of that then graded the outside toe 0% to "face" surface. That graded it right up to where the outside toe elevations met the inside bank slope. Result: Featurline along inside bank with matching elevations based on outside toes.

Thanks for the help

[troma]

Sorry, I thought you already had a "face" surface. So my instructions lacked that step. But otherwise we're in agreement, I think.

[el.Topo]

wouldn't it be simpler if you create a stepped offset of the feature line at 0 elevation difference in a secure distance beyond the berm limits

and then create a surface from these 2 breaklines so as to get the 0 contour from the volume surface...

I agree on the extraction of the volume surface's 0 contour for sure 😉

[fcernst]

Command: _MinimumDistBetweenSurfaces

[el.Topo]

even better! no need for a volume surface...

[Joe-Bouza]

To each his own I guess, The grading makes the offset and surface at the same time, no?

[Feckit]

Create a stepped offset to the correct (inside) side at a distance you know will be well past the intersection point.

Create a surface between that new line and the original.

Use the MINIMUMDISTBETWEENSURFACES command to create a 3D polyline which is the intersection line that your looking for.

Kind Regards

Feckit