This video series about soil is really interesting: https://www.youtube.com/watch?v=uUmIdq0D6-A

Looks excellent, thanks for the recommendation. Even though for my purposes, chemistry isn't that important, as we're doing mechanical simulation.

Mechanics or chemistry?

Mechanics. The virtual building aspect is in the foreground.

The main reason I asked was because I recently saw a show where a scientist was studying the chemical composition of soil under decomposing animals. They are trying to determine the situations under which fossils were formed since it is extraordinarily rare for remains to actually form a fossil.