KC wrote:

-snip-
I've seen them level a sinking corner of an office building slab by
underdigging down about 24", pour a small 4" slab, let it dry, insert
several jacks between the new & old slabs, get the old slab level,
then fill the whole thing with concrete leaving the jacks imbedded in
the concrete. A real red-neck fix but it worked.

I'm making a much smaller hole- and trading out my jack for a chunk of
galvanized pipe- but in general that's my plan.

Now to find that grout pump. . . .

Jim