While the 'cover with dirt by raising' won't work, cut and cover along with using something like a boulder, altar, burial chamber or troll cave and dig under them as your starting point for looks/effect/atmosphere might be the closest you can come in this game.

I'd dig the floor of the 'tunnels' portion down to about 7 meters so you can play around with an authentic seeming uneven floor. If you dig in a non-cardinal direction your tunnel walls will look more jagged. I'd use a double layer covering, flooring material up top, 26 degree peaked roof sections below - depending on lighting you might want to put a third layer of stone flooring as a ceiling. Maybe some of the stone pieces might give you a sort of stalagmite look.

Of course for living areas, and other parts of your base you can easily justify the use of stone materials.

Bad part is.. I don't think it'll stop too many mobs so raids will still require some sort of external perimeter defense Maybe just something to slow them down while you portal to an above ground redoubt somewhere nearby.