3d model (solid) of an existing retaining wall with non-planar lines?

Rhino Rhino for Windows
1

I have surveyed 3d-lines of an existing retaining wall. The lines are top front and bottom front of wall and non-parallell and non-planar. Is there a way to get a solid with for example a thickness of 0.3 meters to the backside of the retaining wall?

retaining wall
retaining wall1930×980 77.6 KB

2

loft the curves or duplicate and trim the existing surface, then use offsetsrf you can flip the direction if needed

3

surfoffset
surfoffset546×470 46.9 KB

Surf offset does not work properly, I guess it’s because the lines are not straight and non-planar…

4

please post your file

5

Mur test.dwg (782.1 KB)
Red line is bottom front wall.

6

Hei Annette -

I’d offset the curves with the Loose option. Loft with straight sections or use EdgeSrf. Join and cap. You’ll need an EdgeSrf on the final non-planar cap.
MurTest - Maybe.3dm (2.5 MB)
-wim

7

Thanks a lot, this looks perfect.