Water behind vinyl walls

Our new pool has been "bubbling" since installed 3 years ago after heavy rainfall.
Coping installer blaming pool shelf design.
Pool manufacturer blaming coping installer.
PB not sure the problem.
This pool owner at wits end!
Facts:
-tumbled coping without cement in-between
-deck-o-seal between coping & decking
-freeform vinyl pool
-only evident after heavy rains
-will happen intermittently around all areas of pool
-subsides after a day or so of dry weather

Any ideas as to what this may be?
Thanks,
Beth

Maybe it will be clear to someone else, but I have no idea what you mean when you say your "pool has been bubbling". I assume that you mean bubbles are coming out somewhere, but that's all I can figure. How coping, or a pool shelf, could make a pool bubble is more than I can guess.

. . . if you mean that water appears underneath your liner, as trapped 'bubbles', then that's something else.

Simple hydraulic principles govern that: if the water level in the ground around the pool is higher than the water level in the pool . . . you'll tend get water 'bubbles' behind the liner, regardless of pool shelves, coping, or any other such thing. If they water level in the ground is NOT higher than the water level in the pool . . . you will NOT get water 'bubbles' under the liner.

I suppose it's possible to get runoff, or gutter drainage, entering the ground -- behind the coping, maybe? -- so that the ground water level just around your pool is higher than the ground water level generally.

Welcome to the Forum, Beth!

Ben's got the right idea. You've got a ground or surface water problem (the 2 have similar results - i.e. pockets of water 'bubbling' the liner- but have different causes and fixes)

I'm gonna guess that you either live at the bottom of a hill and/ or have clay soil/ hardpan. Pics would help (a Google Earth shot of your property would be nice).

To fix the problem you may need to install curtain drains or a well point(s). Give us some more info and we'll help decide the best way to keep this from happening again. Do you know if they hit water when they installed the pool? (if so, the PB may already have a well point in place, but I imagine he would have mentioned that) I would really like to get a 'picture' of the topography of your yard.

Please help me help you by answering my questions:)