I bet the belly strap came loose from the upright and since it couldn't push it back it pushed up. The fasteners may have rusted out.
I was going to say the same thing. I would drain the pool and myself and see if it can be repaired, if not, I would just buy a new pool. My guess it is a root or stump pushing up! This is a bummer, you don't want this the first week of summer!! Could still be repaired/replaced and running by the forth!!wetchem said:I'm on the phone with my friend. He said that from what I described he really did not need to see the pictures. Without seeing the pictures, his advice was to drain the pool ASAP :!: :!: . His reasoning is that more than likely the adjacent supports have been compromised thru a combination of twisting, shifting from true, and some lifting. He also suspects that the root cause is that the anchoring bracket the vertical was affixed to has failed from corrosion and that more than likely the other retaining brackets may also be in some state of corrosion.
He concurs that when the retaining bracket failed that the buttrace forced the vertical to heave. The Vertical being attached to the cross-rail may have twisted the adjacent verticals. The failure of the vertical has now forced the remaining verticals to take its loading - the concern being that if their brackets have been compromised then their failure is assured with the additional load. IF they have been twisted then their buttracing is not taking the full loading for the design and they may fail, worse, with the point of contact nolonger true, the failure will allow the wall to break as the vertical will not heave but will instead twist out of line with the buttrace.
From my own engineering background (started out as a chemical engineer) combined with what I understand from plane old physics, this pool is in trouble!
IMHO - Drain the pool
-wc