How are buildings like skyscrapers in the middle of cities demolished without hitting surrounding structures?

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How are buildings like skyscrapers in the middle of cities demolished without hitting surrounding structures?

In: 2

Either through a controlled explosion (where you use small amounts of dynamite with precisely controlled triggers, to collapse the building in stages,) or through deconstruction.

270 Park Avenue in Manhattan was a 700 foot tall steel skyscraper, and it was deconstructed a few years ago. They basically surrounded it with scaffolding, and pulled it down in pieces. Here are some pretty tasty photos:

https://newyorkyimby.com/2021/04/270-park-avenues-demolition-wrapping-up-as-new-superstructure-rises-in-midtown-east-manhattan.html

Careful engineering. Stuff wants to fall straight down.
So use explosives to knock out the supports in the center or on one side, so the weight above starts falling *that* way. Buildings aren’t built to survive being dropped a few floors; they’ll crumble as they hit.

You have to destroy the supports in a building in a particular way that makes it so one floor falls directly onto the one below it, and the process repeats until the whole thing has fallen in on itself. They use explosives timed just right to allow this to happen.

Modern buildings are designed to facilitate this. they collapse into themselves instead of falling over. Most of the time.

https://www.youtube.com/watch?v=vRLShJW5drE You can see in this video, the flashes that move along the building. those are the controlled explosions destroying supports.

you have currently 2 methods for this:

Controlled detonation: this is where you have thru a carefully setup sequence thebuilding collapsing on itself in stages(you can do this on the whole thing at once else its no longer controllable as the lower levels breakapart from the sheer weight and blow the debris outwards.) you basically want the upper floors ot collapse in order towards the floor directly below them.

Deconstruction: where the 1st option isnt ffeasable you have teams essentitally reversing the buildining process, this is singificantly costlier and slower but as an upside you can end up with recoverable materials.

The art of implosion. My favorite kind of explosives are used in exactly this sort of situation.

They (explosives) are placed very specifically, to cause an inwards explosion, instead of an outward explosion. And it requires fine tuning and placement.

You can’t just set the explosives in any old place. You have to know the building. Memorize it’s blue prints and pick exactly the right points to set the explosives so the building collapses in on itself. Instead of sending chunks flying miles across any given city.

Honestly? It boils down to math. So pay attention in class kiddos!!