That's not what we meant by top-down.
January 11, 2012 10:23 AM   Subscribe

Buildings being torn, literally, down[wards].
posted by dmd (27 comments total) 7 users marked this as a favorite

 
This should be a videogame and not something people actually do.
posted by 2bucksplus at 10:26 AM on January 11, 2012 [4 favorites]


I cannot look at this without picturing the excavator going just too far to one side and tumbling down 13 stories.
posted by shakespeherian at 10:26 AM on January 11, 2012


The ground-based cranes are designed to lift, not dig, so using them to reduce the heights of condemned buildings is not a viable option.

Yes, heaven forbid you use a crane out-of-spec. You should be using the excavator out-of-spec.
posted by DU at 10:28 AM on January 11, 2012 [4 favorites]


Saw this happen with a building in Chicago next to the Board of Trade that eventually became the new bond pit building. They had a Bobcat with a jackhammer on the back and a small front end loader on the front (natch) work its way down floor by floor demo-ing the building. Almost did a floor a day.
posted by JohnnyGunn at 10:29 AM on January 11, 2012


The Maths Tower in Manchester was also brought down in a similar way a few years back. I thought it was neat when I learnt how they were doing it, but I guess that there was far more safety awareness.
posted by Jehan at 10:32 AM on January 11, 2012


you forgot the einstürzenden altbauten tag.
posted by b1tr0t at 10:38 AM on January 11, 2012 [7 favorites]


Demolition of the Deutsche Bank Building next to the WTC site.
posted by Combustible Edison Lighthouse at 10:49 AM on January 11, 2012


Shanxi Science and Technology Hotel

Huh.
posted by Sys Rq at 10:49 AM on January 11, 2012


"The Maths Tower in Manchester was also brought down in a similar way a few years back. I thought it was neat when I learnt how they were doing it, but I guess that there was far more safety awareness."

Yeah, I imagine some PRC contractors saw this safely being done in the west and decided to go ahead and create the situations depicted in the link, ignoring the fact they in the west it's specially built and modded light weight bobcats doing the work on structures that were at least originally well built and of sound design, as opposed to a full size Heavy Construction Excavator on top of a building that only lasted a year before becoming unfit for human habitation.
posted by midmarch snowman at 10:58 AM on January 11, 2012


Demolition of the Deutsche Bank Building next to the WTC site.

There is a huge difference between breaking up the concrete and cutting the columns out, and putting a big-ass shovel on the roof and digging until you are down.
posted by eriko at 10:59 AM on January 11, 2012 [1 favorite]


Yeah, the Bobcats and motorized jackhammers are specialized pieces of equipment that weigh less than a family sedan. Excavators are an order of magnitude heavier.
posted by Slap*Happy at 11:03 AM on January 11, 2012


I'm not entirely sure that those are normal excavators. The article seems to have been written entirely on speculation based on some photos the author found.

I've seen a handful of rooftop demolitions in the US (admittedly, not with such large/heavy equipment), and it's not terribly uncommon for interior/facade demolition to now take place by simply plowing the building's contents through exterior walls with a bobcat.

The top deck of the Alaskan Way Viaduct in Seattle was also removed using a very similar method.

It wasn't done with excavators, but the Deutsche Bank Building in NYC was deconstructed piece by piece, instead of by traditional demolition methods after being damaged on 9/11. Apart from being a novel project, the contractors had no idea what they were doing, and the demolition project was the site of numerous fatal accidents, an Ayn Rand-inspired embezzlement scheme, falling debris, and a fire.

The photo shown depicting a "shoddily constructed" Chinese building that literally fell onto its side supposedly actually had very little to do with the quality of the building's construction. I haven't followed that particular story all that closely, although my understanding is that the building's engineers/architects didn't consider the soil density underneath the building, and adjacent construction/excavations along with heavier-than-usual rainfall allowed the building's foundations to be undermined, ultimately resulting in the structure toppling. (tl;dr; Somebody fucked up, but the building didn't collapse because Chinese construction is inherently inferior)
posted by schmod at 11:22 AM on January 11, 2012 [3 favorites]


Yeah, the Bobcats and motorized jackhammers are specialized pieces of equipment that weigh less than a family sedan.

Bobcats are a lot lot heavier than they look - the "compact" T-110 model starts at 5,200lb, and the larger ones weigh closer to 6,000lb, especially with attachments like the jackhammer, so more like twice the typical family sedan. Bonus - in a fairly small area, so the ground pressure is pretty high.
posted by kcds at 11:40 AM on January 11, 2012


Seems immensely time- and labor-intensive. How is this more economically viable than a controlled demolition with TNT? Are there other factors besides money worked into the decision?
posted by Gordion Knott at 11:52 AM on January 11, 2012


Gordion Knott: "viable than a controlled demolition with TNT? Are there other factors besides money worked into the decision?"

A lack of skilled explosives experts? Demolishing a building with explosives in a densely-packed urban environment is incredibly difficult, and still dangerous even when done by experts.
posted by schmod at 11:54 AM on January 11, 2012


This seems like the inverse of pulling yourself up by your bootstraps.
posted by spitefulcrow at 11:54 AM on January 11, 2012


I'm impressed the floors can handle the weight.
posted by smackfu at 12:07 PM on January 11, 2012


The "Get Carter" car park in Newcastle was demolished using a sort of claw attachment on top of cranes. I suppose that's only viable to a certain height, though.

Seems immensely time- and labor-intensive.

Chinese labor costs are an order of magnitude lower than in the West. Additionally, many of the cities are full of unlicensed workers from rural areas who will work under the table for even lower wages. Conversely, Chinese rule of law as it relates to land titles and liability is weak. It's a witches' brew.
posted by dhartung at 12:24 PM on January 11, 2012


Even though it was used correctly for a change, I can no longer stand the word "literally".
posted by Liquidwolf at 12:25 PM on January 11, 2012


You can also do it the other way around, and demolish it floor-by-floor from the bottom up. Yes, really.
posted by Jakey at 12:25 PM on January 11, 2012 [2 favorites]


I cannot look at this without picturing the excavator going just too far to one side and tumbling down 13 stories.

I have to ask, what's the point of the safety vest and hard hat?
posted by odinsdream at 12:46 PM on January 11, 2012


tl;dr; Somebody fucked up, but the building didn't collapse because Chinese construction is inherently inferior

Construction necessarily involves a proper foundation, though.
posted by odinsdream at 12:47 PM on January 11, 2012 [1 favorite]


Jakey: "You can also do it the other way around, and demolish it floor-by-floor from the bottom up. Yes, really."

That's kind of awesome, and actually seems to make a lot of sense if the building's structure allows it.

A few years ago, DC converted a segment of elevated highway into a surface-level boulevard. Instead of spending the time and money to construct a ramp between the still-currently-elevated portion and the new road, they used a similar technique to lower one of the remaining segments of elevated road on hydraulic jacks, effectively converting it into a ramp. It was a pretty cool bit of engineering, and the results of the project had a tremendously positive effect on the neighborhood.
posted by schmod at 12:58 PM on January 11, 2012 [2 favorites]


Rooftop excavators? On my multistory highrise building? It’s more likely than you think

Now I'm thinking of a certain image popular on fark.
posted by Pruitt-Igoe at 4:37 PM on January 11, 2012


schmod, that John Galt Corporation story is amazing. Simple "irony" seems inadequate.
posted by sneebler at 5:47 PM on January 11, 2012


They did something like this to a building at the University of Alberta a few years ago; here's my grainy photo of the demolition in progress. As I recall, they explained at the time that they wanted to recycle a bunch of the building, and explosive demolition wouldn't allow that.
posted by stebulus at 8:24 PM on January 11, 2012


We must kvetch about how slipshod and hasty Chinese construction is, or we would feel terrible about the glacial pace of our own construction. The actual quality of Chinese construction is beside the point.
posted by tehloki at 10:48 AM on January 12, 2012


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