Feature line on edge of corridor busts surface

[b.stark]

Does anyone have an explanation for the bust in the surface in the image?

What is happening is that I am setting a feature line on a lot line that originates from the edge of my road corridor. The corridor surface comes from a different drawing and is dref'd into my "finished grade" drawing. Then I start my lot grading using the corridor surface to set the beginning elevation of my feature line and grading into the lot from there.

As you can see from the images, at random points along the corridor(it does not happen everywhere), it completely destroys the curb of the surface. Its like the triangulation from the corridor surface forgets the top of the curb and the sidewalk/parkstrip and builds directly from the curb flowline to the feature line I created.

There are some workarounds to get around this but I am looking for an answer to why this is happening. A feature line on the edge of a corridor, at the elevation of the corridor should not cause the triangulation to bust from a point several feet away.

Thank you in advance.

[Joe-Bouza]

It probably has to do with the build order.

Are you adding feature lines to a corridor surface? If so dont. You will have an easier time pasting the corridor into an empty surface and adding your off road modifications. Much easier controlling the build order

[tcorey]

You mentioned having parcels. If the feature line and the parcels are in the same site, the parcels can affect your gradings/surfaces.

[b.stark]

Negative. Corridor surface is in a different file and data referenced into my "final" surface.

[b.stark]

I am not using parcels. Just good old 2d linework in a base file that I am designing feature lines over, for lack of a better word.

[Joe-Bouza]

Reading is FUNdeMental. Sorry for not digesting your thread fully.

I am setting a feature line on a lot line that originates from the edge of my road corridor... Does this mean you are relying on elevation from surface to set the Feature line? Seems like an inconsistency in the edge of corridor elevations. Have you compared them in this area?

I might consider and alignment and surface profile from corridor dref to you final surface and create feature line from alignment/ profile. Then I know the feature line and corridor were in sync

[b.stark]

I do rely on an elevation from surface. What I do is place an elevation label at the endpoint that references the corridor surface and then either snap to that label or use the quick elevation editor to set the elevation to the surface.

I like the idea of using the alignment and surface profile suggestion, I hadn't thought of that, thank you, and will look at using that in the future. These projects where not too many lots front a road, I can set those elevations pretty quick.

But really what I am trying to get to the bottom of is why this is happening when I know my FL elevations are exactly those of the corridor and in very random places, it breaks the triangulation of the corridor, skipping "breaklines" (the top part of the curb assembly) that are definite parts of the corridor.

Thank you for your input

[Dexterel]

upload your dwg and you will get all explications.

[Joe-Bouza]

Hidden in my a message is the build order. move the corridor surface up or down in the build order and see if it changes

[b.stark]

Pretty much the easiest solution is to make the frequency of the corridor tighter and it makes it go away.

I just cant wrap my head around why you need to do that. Before the feature line, the surface is perfect through the corridor cross section. Add the feature lines and at completely random spots the surface then builds from the gutter flowline to the feature line ignoring all other corridor information along the way.

[wfberry]

Have you turned on your TIN lines.  Most times this gives you the WHY.

Bill