A guy from some Biotecture Institute invented what he called an Iron Butterfly for ramming dirt in tires. Imagine a Pipe with a T handle on top and power coming off of that. A single horizontal hydraulic piston on one side at bottom pushing one way and metal ram pushing the opposite way. Or imagine this thing having an I shape with the bottom of it being the ram. I saw pictures of it but can’t find the web site now or the images. If you google or youtube for this all you get is rock band crap.
What climate do you live in where you intend to build this eartship? how many inches of rain per year does it get? how humid is it? What are the outside temperature extremes?
What others are reading
For films about individuals and technologies for living off the grid X