Not an engineer, but . . .

[HADESgou]

Have any of you tried to drain a pool in florida? my cousin drained his pool to resurface it and the "Hydro-static pressure " popped the pool out of the ground. if you dig down five feet in florida you will find water, it is possible that if they do not have dry well pumps under the lagoon then parts of it may pop up. not sink or fall in although the side walls are dependand upon the floor for stability.
Hey wait a minute didn't I see a picture of the lagoon already drained if that is true then whats the big deal. May 3rd rehab photos.

 

[BalooChicago]

Originally posted by HADESgou
Have any of you tried to drain a pool in florida? my cousin drained his pool to resurface it and the "Hydro-static pressure " popped the pool out of the ground. if you dig down five feet in florida you will find water

This is not a backyard pool, and is likely completely above the water table, or at least the vast majority of it, given the way the park was built.

 

[McArcDes]

As I recall, the Magic Kingdom was built about 14 feet above ground level to help mitigate some of the "swamp" proplems. I would think that this means that if the top of the Lagoon is even with the paving in Fantasy land then the bottom would be at about ground level. I am not really sure of how deep the lagoon is. I would also expect that the whole Lagoon is built like a huge sprayed concrete pool where the sides become pretty much like free form concrete retaining wall with lots and lots of rebar in it. i.e. very very stong.

Wouldnt this mean that the Hydrostatic pressure would not be a problem and once they took out those walls there would be very little to fall in on its self?

"If" they were worried about any collaps then they could just leave the sides in place and fill in the middle and then take out the sides after the center is filled. They kind of did this in reverse here in Boston for the "Big dig".

 

[BalooChicago]

They will probably put temporary shoring in place prior to removing the walls. This is done all the time when excavating foundations.

 

[McArcDes]

Or they could just excavate the filled side of the wall too and relieve the back pressure that way...so many possibilites....

 

[marni1971]

If they are so worried about a collapse now, what has happened between now and the last major refurb when it was totally drained and had Engineers painting it? Strange don`t you think...

 

[Mr Smee]

Maybe there is just no real timetable for completing this project. No one is even sure what to do with the area other than to fill it back in.

 

[Lee]

No part of the lagoon is "underground". It sits on the same level as the Utilidors.