Bricks, Masonry, Asphalt and Concrete - filling in a pool

I have a 16' x 32' inground pool I am filling. I want to put a 30' x 40' garage on this spot. I plan on using 6" of gravel and 6" thick slab. I want to know how long I have to wait for the ground to settle before pouring the concrete slab, and can I speed up the processes like filling the hole in layers and using a gas tamper to compact the durt. My main concern is not having the concrete to crack in the future.

Thank for any help

Is this a Gunite Pool Shell? You had Better check with your Local Building codes on the proper procedure on filling in a Pool Shell.

I would think if the fill is compacted properly as you go you can Build on it immediately.

I would breach the bottom of the pool in a few spots so the gravel doesn't hold water or you might have moisture problems in the garage.

That is a good point by Hell Razor!!

Thanks for the advise. the pool had a liner I removed it and the bottom is packed sand. the sides were metal and I removed them, so I have a big hole in my back yard.