Did you check the gravity? The bubbles mean nothing. Check your gravity with a hydrometer always. I learned that the hard way with an IPA. Wife was none so pleased.
The sugar in apple juice is 100% fructose, as far as I know, and will ferment out completely with champagne yeast. You should expect a final gravity of 1.000 or even below. If you don't nuke the yeast with some kind of sulfite, it'll keep fermenting until there's nothing left.
My mildly-educated guess is that your cider wasn't done fermenting and you set youself up with the perfect recipe for bottle bombs. One thing that I've learned in this hobby/obsession is to use the tools that have been developed to test things; gut instincts are for the experts, which I ain't one of.
Best of luck. Don't give up, just clean up the messes of the bombs and plan your next attack.