How do they do that.

[CHJ]

Anybody go past this site and see how they removed these obviously self supporting floors.

 

[flying haggis]

Gut the inside and hold up the upper floors with cables fixed to the central core perhaps? As there appears to be bracing under the visible floor it has been supported/hung somehow.

 

[riclepp]

I believe that they were built in reverse to normal buildings in the late 50's early 60's and the take down is the reverse of the build up. I don't think there are any support wires, the floor is were it all happens, remove from the outside to the middle then move up a floor. Then there are the ones where the floors are lifted up then secured in place and the take down is reversed.

 

[Harbo]

It looks like each floor is cantilevered from the central core?
Just need to cut it off there and gravity will do the rest?

Rod

 

[Dusty]

I think you will find that in the construction of these types of buildings that the central core is the spine of the building and the floors are built from there . Normaly the spine is constructed of concrete and is the real structural design and the rest is concrete reinforced and cast on site to suit . as long as it is balanced it should be fine . you will normaly also find the spine doubles up as lifts shafts so no space wasted .
re the picture ,Personaly cant see why you would do it like that apart from waste disposal would be kept in the foot print but I bet the Health and safety officer had a field day .

 

[Steve Maskery]

IIUIC(one of) the Gaudi building in Barcelona is built similarly. The floors are cantilevered from a central core. The advantage, from Gaudi's point of view, is that the outside can be any shape you want and the insides can be re-formatted at a whim.

It's quite astonishing, but photography is difficult as you can't get very far back.

 

[CHJ]

Even if the original lifting mechanism is in place and serviceable, which I see as most unlikely, I would not fancy being the individuals that cut the floor anchors from the central core.
I was wondering if there are multiple lowering winches fixed between the floors to lower the the detached layer just leaving the cantilevered 'roof ' structure with no working platform beneath it.

 

[Steve Maskery]

I agree that it is a fantastic feat of engineering.
S

 

[henton49er]

Looking at the photograph, there appears to be a square lattice of beams underneath the floor about to be demolished. It is difficult to tell whether this is the original construction or something installed to facilitate demolition. In this type of building, with all the services, lifts, stairs etc in the central core, the floors will be cantilevered from the central core, as others have observed. In this case it could well be cantilever beams with lightweight floor panels spanning bewteen the beams. The demolition process would be to remove the floor panels, then the beams.

It is also possible that the beams might be in sections making demolition much easier; but the principle would be the same.

 

[Jake]

All the details you could ever want will be on this thread somewhere, between all the noise. See you in a few weeks:

http://www.skyscrapercity.com/showthread.php?t=415718

This and the old Fenchurch St scraper were of an odd top-down construction, with each floor suspended from the top - a clever use of tension to reduce materials but made demolition a right headache. They took the bottom floors out the usual way by breaking them out and using the core as a rubbish chute - the only(!) difference from a normal demolition was that they had to construct a platform under the floor to catch the debris, which climbed the core as they went upwards, instead of just collapsing it onto the floor below. I think at about the stage that photo was taken they did a whole load of work to take the load off the top of the core and make them cantilever off the core, and then went top down in a more conventional way.