above-ground pool failure 1

[PSUengineer1]

An above-ground swimming pool collapsed. Water was reportedly in the pool at the time of collapse. I have attached photos. The pool is approximately 30 feet in diameter and about 4-feet in depth. No tears were observed in the vinyl liner. Rust is present on the screws attaching the coping to the uprights (see photo 10). No significant corrosion is present on the underside of the same connection (see photos 11 through 13).
My thoughts:
1. Corrosion of the structure is not why pool collapsed.
2. water left the pool and the walls collapsed, perhaps due to wind.....but, how did water get out of pool. I saw no tears in liner. Pool owner reported that pool was full of water at time of collapse (bet he was not home).

Any thoughts? I appreciate any feedback.
Thanks,
jimjxs263

 

[hokie66]

Maybe it was pumped out, or left by a leak in the recirculation system.

 

[pbc825]

My knee-jerk reaction is a poorly designed product from the manufacturer (the overwhelming majority of cause in my experience). There's no significant corrosion in the photographs.

 

[JStephen]

Possibly kids or livestock messing with it, possibly overfilled, possibly ice damaged at some point in the past.
You sort of expect stuff like this to be pretty marginal in strength, too.

 

[Ron]

Pool failed from the bottom of the wall/support system as it (the wall) fell over the liner that was pushed under it during failure. This was likely caused by the wall coming out of its retaining slot. Could have been a fastener corrosion problem at the bottom, not the top. The verticals are attached to the bottom rail which forms a slot for the wall. If a vertical failed at the bottom attachment or the track failed at a lap/splice connection, this is the pattern of debris you would likely find.

 

[chicopee]

One scenario could be that at one time the pool liner failed and the water emptied out of the pool. The defective pool liner was not immediately replaced and the wall collapsed inward. The wall was straigntened, a new pool liner installed and the pool was filled during spring. At that point the bottom of the wall had buckled and had that familiar elephant foot shape which could not be strainghtened when the pool was being filled up. The pool was good for several seasons,however, in the end the wall collapsed inward due to the buckled bottom. That happened to my above groud pool.

 

[Splitrings]

I am with Ron on this one. Looks like the liner "slid" out under the wall. I'd guess at the left side of your picture #1 is where it initially started. That section of wall is diplaced from its original location considerably more so than the rest of the wall. As the water rushed out the tension remaining in the wall pulled that section towards the middle.

 

[Compositepro]

This type of above ground pool is a delicately balanced structure. Clearly, in this case, the liner extruded under the pool wall and lifted it. This would be caused by the liner not being securely clamped at the top of the wall . As I recall,a critical step in setting-up this type of pool is placing a fillet of sand at the inside base of the wall. Over time this may have been washed-out in a spot by leakage. The only thing holding down the wall is its weight (almost nothing) and attachment to the liner at the top of the wall.

Leveling these pools is also very critical and there can be settlement over time, particularly if the ground gets soaked.