Travis and Dillon, thank you for your responses so far. Much of what you have mentioned, Travis, I've come across in one form or another looking at
cob, air-crete, foam-crete, and other variations on concrete and I'm liking the ideas that you've added here. I had seen other commentary mentioning the 'tilling' of concrete mix into earth and was a bit confused ..... wouldn't it eventually just break up into millions of tiny grains of earthcrete and be swallowed up by the clay?
But I am liking the idea of excavating about 1 - 1.5 ft of the clay that is closest to the building to create a channel ~ 10 ft wide, then dumping concrete/quikrete into the channel to form a layer and then following with the tilling idea that you mentioned. By then back-filling with crushed rock/coarse gravel, the final topping could be '
class 5' road gravel.....the latter being the abundant and preferred surfacing for the rural gravel roads in the area. Even in these cases, I suspect I will need an outlet: Water percolating into the rock/gravel mass will need to go somewhere and there will need to be some sort of French drain or drain-tile effect to allow water to flow to a nearby excavated ditch. What we are fighting in all of this are the clay fines and sediment that clog, in a short time, any filtering-type contraptions. That said, we do have a large roll of 'cow carpet' on hand,---a geotextile that we could employ to try to separate the clay from the rock. As Dillon noted, this might be the time to "roll out the carpet" and put it to work. Gutters have been employed in the past, but they've been rather cheaply installed to save on cost and we've paid the price for that....the ice and snow sliding off the metal roofs rips them apart pretty easily. So we are revisiting that possibility with something more heavy-duty.
Thanks again and I hope more weigh in with their own experiences. Even as it's great for growing crops, the depth of clay and lack of slope are key impediments to success on these efforts, but your comments give me a good place to start. Needless to say, since the entire Red River Valley is essentially the lake bed of the ancient glacial Lake Agassiz, it has a long history of holding water. By way of education, below are some of the considerations that the
city of Fargo needs to contend with regarding this matter, probably not too different from building on the sands of the Atlantic coastline! >>>
"Forming the remainder of the materials are sediments deposited into Lake Agassiz. Approximately 85 ft (26 m) of the gray, slickensided, fat clays of the Brenna/Argusville Formations are overlain by 20 ft. (6 m) of the tan-buff, laminated silty-clays of the Sherack Formation. We seldom can view the contact between the two formations, although it is occasionally visible along the channel of the Red River during times of low water flow. Within both formations are occasional cobbles and boulders that appear to represent dropstones: rock debris that fell off icebergs floating in Lake Agassiz.
.....Where the Sherack and Brenna formations are unconfined, their high plasticity leads to slope instability. Because the channel of the Red River and many of its tributaries incise across the Sherack/Brenna contact, the weak characteristics of both formations lead to extensive mass wasting problems. Examples are prevalent along the valley walls and channel margins of the Red River and its tributaries throughout the Red River Valley."
--https://www.ndsu.edu/fargo_geology/caissons.htm