Wofati engineering questions for Paul - real world applications and experience

The purpose of this thread is to prepare for an upcoming consultation I have with Paul, and it is my hope others who are interested in this type of building will find the information useful. I am in the process of building a Wofati inspired home on my land in central Missouri and ran across an engineering question/problem and needed to talk to one of the few people on the planet who understand and have experience with this type of building. I have been to Wheaton Labs and visited the Wofatis and was truly inspired by them.

I say "Wofati inspired" because my building does not exactly fit Paul's definition, however it is heavily influenced by Paul's Wofatis and the same builders/authors that informed the Wofati concept. My home is a pole structure made from trees cut off my own land (mostly) and it will have an earthen roof and here is where my engineering problem creeps in. I did try to contact local structural engineers but despite multiple phone calls and emails I couldn't get any of them to call me back. Its probably for the better, I suspect they are super busy and are more interested in pressing the easy button (copy/paste) for another stick frame house garage door header than figuring out what I've got going on.

My design calls for posts on a 8x12 pattern for most of the building, so each of these posts are carrying 96 square feet of roof. I am doing my calculations with a 200 lb per square foot roof load. That was figured by adding 1ft of dry dirt at 80 lbs per sqft, then insulation and waterproof membrane, then 1ft of wet dirt at 100lbs per sqft. then adding central Missouri's snow load of 20lbs per sqft. Total is 2 feet of earth on my roof and 200lbs per sqft of a roof load. For a single post carrying 96 sqft of roof, multiply 96 by the 200 lbs and you find that that post is carrying 19,200 lbs of weight. I have read Mike Oehler's book on the subject, and John Hait's on annualized solar. I had done all this engineering about 5 or 6 years ago when designing the structure to figure out how big the horizontal logs had to be to carry this roof and I feel really solid in those numbers.

Like I said I am in the process of building, I've got 13 posts in the ground and am trying to make progress. My conundrum arrived last week as I was putting in a vertical post that was a little smaller in diameter than some of the others so I thought I would double check it could hold the weight. I turned to my new structural engineers Google Gemini and Grok. These tools were not around when I first started working on the design but I now use them to double check stuff. I asked the AI how much a weight 7 inch diameter white oak post could support, and after a few back and forth questions arrived at the conclusion that the post could indeed carry the weight. THEN it asked me if I wanted it to design a footer for this post to sit on. This had not occurred to me at all. Oehler's book doesn't mention it other than (paraphrasing) "if you want to, toss a large rock in the hole". I've scoured the Wofati build threads on permies and it seems that they just put posts in the ground. But now AI is asking if I want a footer designed, so I say "sure, design a footer for 19,200lbs" This thing comes back and says I need 42" by 42" concrete pad 10 inches thick under every post! What?! No! My soil is basically rock and clay so I tell it that and it amends it's recommendation to a 31" by 31" concrete pad under each post. Gemini claims that without the footer to spread the load and this kind of weight pressing down on that small of an area, that my post is just going to sink into the ground like a giant nail. But Mike and Paul don't have footers so what gives? So I stop working and decide to ask someone who has experience in this arena.

I've since revisited the threads on the Wofati builds and discovered that 2 of the posts at Allerton Abbey had indeed sunk but there's a lot more than 2 posts in that building, what was it about these 2? No mention of the posts at Cooper Cabin, everything there seems fine. So I decided to get Paul involved and talk it out and see what he has to say about this. Follow along if you're interested.

Here is a picture of one of the posts, you can see the rocky spoils from digging the hole to the right of the post. I'm digging with a 4 ton mini excavator and it has a hard time getting through this stuff. My process so far has been digging a hole, then putting in a few inches of crushed gravel and compacting it, then placing the post on the compacted gravel, then backfilling around the post with more gravel for drainage.

Another picture shows some progress of the build.