It sounds like you want to increase the drainage of your soils.
Gypsum is great for some clays. I would get some gypsum grit and dust, and maybe some larger pebbles, along with a bunch of woodchips, spread it out in a saturated test area that, should it work as intended, will take water away from your building foundation. I would fork this in, but you can till.
This should give the clay particles something other than themselves to stick to, opening spaces around the different-sized particulates to admit more water and air.
I would also put the critters in the soil to work for you. If you can make an oxygenated
compost extract and a fungal slurry and inoculate the amended site with it, you will make more worm food, which will draw worms (or you could introduce some) that will actively aerate your soil for you.
If you dig drainage ditches in soil that simply doesn't let go of water, the ditches can remain dry while your soil remains saturated.
Let us know how it goes, and good luck.
-CK
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein