We have been trying to perform what we call "simple" grading objects with CIVIL3D as well.
Just returning from the AU in Vegas, whole class on grading objects ended up to be a joke, in that being told the Civil 3D grading objects are still "unstable" and continue to use LDDT.
Go figure. We get mixed results, crashes, footprint not moving dynamically, you name it in Civil 3D full release.
Look at your slopes, maybe your missing (under/over) your surface definition your tieing to. Steepen, then work up/down to ensure your hitting your surface match.
Geoff T.
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