Underground geology

Rhino
1

Hello
I am new in 3d modeling in CAD and I need some directions/tutorial to learn how to draw subsurface geological layers in the underground of a topography (plain or a hill). It will be my import file for numerical modeling. I can export easily from a GIS a DEM or a STL file of the surface but then I am stuck. All the online materials I found are for modeling buildings on the surface … is there anything else I didn’t find?
Thanks a lot!
Cheers

2

Hi Paola -
You will need information about those layers and somehow model them. Conceptually, the abstract idea is to just put several boxes on top of each other. The reality will be a lot more complicated. If the layer thickness were to be uniform all over, you could just copy the surface layer to different depths.
-wim

3

This kind of geological modelling usually uses specialized software like Leapfrog, Micromine, etc. However, you could build a simplified model Rhino. But what kind of data is informing the subsurface model? Do you have drillhole data?

4

I can start with uniform flat layer, but usually the layer thickness is not uniform, it has it own shape which a I can draw from a geological map. Let’s say if I have a hill and a flat plane dipping on one side of this hill than I need to trim it with the surface. The surface is complex, it’ a real topography then maybe I need to simply it.

5

Uhm … that is maybe for very complex underground geological modeling

6

Yes, unless you have a lot of drillhole data or perhaps data from controlled-source seismology, you would want to work with simplified geometry. You could probably use QuadRemesh to make a surface that would be manageable.
-wim

7

If you have a geological map, you could import it as a BackgroundBitmap, trace the geological contacts as curves, and then extrude these curves along the approximate dip angles (if you have them, or can work them out)

8

thanks a lot, I will try this

9

Thanks I will try and do this as well, sounds a bit of magic!

10

Drawing two different surfaces in the same place is a mess because you do not know how they will render. I would draw this geology as surfaces rather than volumes. To make vertical cross-section, I would draw vertical clipping plane and I would extrude curves between the surfaces in the same place as the clipping plane.