Fiberglass pool question - can they pop out?

I pool company is putting in a vinyl pool next door. I asked him about fiberglass pools and he said No that they have popped out of the ground after alot of rain. Is this true? And if so, is there a way to install one so it does not pop out? Seems like if you poured concrete along the sides on it to anchor down the side braces, how would it pop out then?

Thanks!

Warren

If the pool remains filled with water, the downward force/pressure (holding pool in) will equal the worse case upward force from the ground water. The pool will not pop out. The problem comes in if/when you drain water form the pool. That is when they can pop out. Same is true of concrete pools. In areas of high ground water, builders will install a drain field/line under the pool (a well point) so the ground water can be pumped out under the pool whenever you need to drain it (i.e. repairs/refinishing).