Bully;10885 said:
Has anybody done one of these before or anything similar? I'll update with more info when I take a look at it.

We did at least 16 this summer! I can't remember the price for the job or how long it took any more, i would guess it was 2 days for one lift.
the eqipment we used was:
- 2 operators
- Diamond floor saw
- fork lift
- 2,5 ton skidsteer
- 2 ton miniexcavator with bucket, hammer, concrete cutter and clamshell bucket.

the lift was "easy to remove", just unbolt the top bolts and lift up the 2,5m high pacage with hydraulic cylinders and stuff with the fork lift. then cut around the lift base so you get enough space for the digging operation, then hammer all the concrete you can hammer.
Dig out the concrete rubble and the gravle around the cylinder pipes.
The ones we did had a 300mm plastic pipe that was covered with reinforced concrete, the pipe went down 2,5m in the ground.
Hammering the walls down in the hole was totally impossible, so a concrete cutter was put on the miniex to crush the walls. because of the difficult depth and shape of the hole we used a clamshell bucket to dig out the hole to remain it's shape. the bottom floor of the holes was the then hammered and dug out with the clamshell (it could reach 2,7m on the 2 ton ex).

for us it was a real pain in the *** project, we had to do it at night (to not disturb the buisness) and the place was really low so no big equipment could fit.

I had really good video and picture footage of the project, but my computer has lost it somehow?

Hope you did understand my bad english

Bully, they are constructed like a hydraulic elevator cylinder. If the building was going, you just have to hook to the caisson and pull hard. With the rest staying, I would try to find out if there is going to be anything going into the ground. If not I would (depending on local codes) suggest to the client that the ram, packing and oil be removed and then the caisson be grouted level with the floor.