This is a shed (previously posted about as in need of extensive
renovation), with a half-assed carport in front, built by a previous
owner. It's a fairly amateurish job and we only keep it around because
it is useful to keep things out of the rain.

The sides are supported by two pipes, about 4-5" dia., some 8' apart.
There is a fifth pipe support in the rear center; the front support was
replaced with a 4x4, I think when we purchased the property. Now that
it's become my responsibility, I've been cleaning up things and the
accessible pipes have already gotten the wire brush and naval jelly
treatment for what isn't really an astounding amount of surface rust.
I've worried about what might be the case below ground, though -- the
pipes just come right out of the dirt, and whatever protectant they had
when installed has long since ceased to do the job.

Anyway, having excavated about 10-15 years worth of accumulated crap, I
got my first good look at the supports on this wall. The middle column
(rear pipe of two) simply came loose in my hand! Down at ground level,
where there's a drainage problem, the support is split at an angle, and
from the "fit" of things seems to have lost as much as an inch to rust.
Fortunately, the framing of the roof and wall, despite what you'd think
from appearances, seems not to miss the physical support here.

Given that I don't want to do the whole-hog rebuild approach, just yet
anyway (there's a non-zero chance the city may order us to raze when we
try to get a building permit). Would there be any value in "patching"
this pipe with one that, say, just fits inside and gets bolted to the
unrusted part of the support up above? I don't see why it wouldn't work
and last at least as long as any of the other columns.

And how should pipes like that be built? Stuck right in the ground seems
a little reckless, even if it did last a couple of decades. I imagine
there are concrete footings, but is that otherwise normal? How would it
be done today? *If* we get to keep the building, I'd like to do this
right someday.