looks like you could build multiple layers and apply linear elastic materials to each
probably a really rough approximation but should work
is there a reason you don't want to do that?
I believe one of the nonlinear materials is meant to approximate soil, maybe blatzko?
Actually i don't know how to apply a soil proprieties to a components.
i maintain the problem below...
Concrete pavement Thickness h1 = 270 mm
Unbound base layer Thickness h2 = 150 mm
this two are laying on the soil...so i created a base model and then i was placed this two components on that base ...but here i was searching for a soil propitiates to apply the base component..but i didn't find soil properties.
Drucker Prager models are used for soil modeling. Requires a non linear analysis. Properties? You need to search the web. Not easy to find in my experience. You can get a place like datapoint labs to test a sample and give you a model for pretty modest dough. Good luck
I'd suggest you consult with your friendly neighborhood Civil Engineer (especially as they are most likely also a P.E.). I know this is something that they have to take into consideration for roads, buildings, etc. Or, head to the closest university with a renowned Civil Engineering program. The professors might be happy to assist.