extend a surface

[andres_t]

Hi

I am working in a corridor where I have to calculate the earthwork. My problem is that the survey surface is not enough in lot of sections, so the assembly can't find a surface where to match.

The existing terrain, in general, follows the slope at the boundary of my surface. So all I need is to extend these slopes beyond the limits of my survey surface.

I tried using edit surface --> smooth surface --> Kriging

But this does not do exactly what I want (and it also modifies my surface, and I want the survey surface to remain intact)

Adding point by point or triangle by triangle to the surface is almost impossible, because it's a very long corridor, and this would take lot of time.

Does anyone know what can I do??

Thanks

[jpaulsen]

Extract the contours and boundary from the surface.
Change the boundary to a 2D polyline with a 0 elevation.
Offset the boundary the required distance, say 100'.
Extend the contours to the new boundary.
Create a surface from the contours.
Create a another surface, paste the new contour surface and the survey surface into it.

This will leave your survey surface intact and will generally extend the existing slope out another 100' from your survey surface.