Observatory / pier foundations

Thanks John. An interesting read.

The opinion seems to be to use a nut just below the bottom flange and
one on top of the flange to hold the flange/ pier down. This avoids
very high tension loads being placed on the bolts (studs) set into the
concrete. And also allows accurate levelling of the pier flange and
thus the uprightness of the pier.

I must say that I have been delighted with the incredible stability of
my own all-welded pier. Despite it not having underground foundations.

In retrospect I might have made it slightly taller. So that if a floor
was placed over the feet (but not touching them) then I would avoid
tripping over them in the dark. Easy for me to modify thanks to the
facilities and materials available to me. But if I was paying somebody
else to do it I would think very hard indeed before finalising any
design.

Regards
Chris.B