Foam scenery and Roadbeds

I fired up my CAD app and imagined using blocks of foam just like I used to use plywood: by judiciously chopping the sheets and inserting shims underneath, you can build super-smooth roadbed automatically. In the spaces between, stacks of foam, possibly inclined, can simulate rock strata. Is that the essential idea?

It seems that the best way to maintain the tunnels, in that case, is just lifting the entire mountaintop off! With alignment pags it whould be simple to accomplish. Am I on the right path here?

 TIA!

   I am trying something new for me. Instead of the usual plywood platform to start with, I have laminated some panels of Styrofoam together. This gives a thick substrate that can be carved for rivers or ditches. I am building a 4.5 by 8.5 foot layout. I will post some pics in a while. I plan to laminate sheets of foam for mountains and hills.

Jacko 

Thanks very much CN Guy, that's a really neat example of scenery mods on the fly!

I have drawn a side view of one end of the layout with contours being carved in foam, with separate angled pieces for the roadbed. That's really cool!

This is a combination plan-view and X-Ray front view; you can see the track above and the vertical arrangement below. I'm really pleased! The mountains naturally have a believable contour, which is really the hard part. The background mountain will be made in bas-relief and will probably look a lot like Mt. Olympus over Salt Lake City.

The verdict: it should be beneficial to vary the "normal vector" of the strata.