From the description it sounds as if you have several issues:
The soil is compacting under load. This can be particularly severe if it has high organic content.
Yes - a 6 foot compost pile that last time I checked was 1/2 " (10' of concrete rubble on top of it) with water flowing through it
From the description it sounds as if you have several issues:
The soil is being pushed down slope by the load.
The soil is moving down slope under its own weight.
Yes to both - attached poor Google pic - some trees have been removed
From the description it sounds as if you have several issues:
The first two can be mitigated by increasing the surface area upon which the structure rests. The last can only be resolved by piers drilled into bedrock of sufficient strength to resist the shearing force of the soil. It also resolves the first two.
Surface area - I put 100's of yards of concrete rubble around it. For years I checked Craigs List for free rubble
Piers drilled into bedrock is the really for sure answer - way beyond my ability to pay for them. What I am going to do is print out your response and give a copy to the next owner
Of course, all this is speculation without pictures of the situation.
I went down there today and took pictures. Good news and bad news.
Bad - the area looks like crap - it looks like a junk yard - very depressing - 2 years ago a storm snapped a 6x12 " beam in a structure next to the villa. For 3 years I have tried to figure out how to fix it. I get very depressed every time I see it
Good - it has not moved in 3 years
Three years ago (Mar 2, 2015) I bought this :
https://smile.amazon.com/gp/product/B006JR8XBG/ref=oh_aui_search_detailpage?ie=UTF8&psc=1And measured 0.00 on a door frame (two readings at right angles). Today I measured again and it reads the same.
Another door frame reads 0.45 lean towards downhill, but I cannot remember if I checked it 3 years ago.
When I built it, I used cheap HF levels.
Actually I do not understand why it has not moved
I will post pictures in a few days, I need to recover from the shock of the mess and damage