"The Taipei 101 Tuned Mass Damper
Between 1901 and the year 2000 there were 91 major earthquakes in Taiwan, 48 of them resulting in loss of life.
The most recent major earthquake was the 921 Earthquake, which struck on September 21, 1999, and claimed 2,415 lives.
-Wikipedia on earthquakes in Taiwan
When you decide to build a 509.2 meter tall skyscraper in a country that historically has had just under one serious earthquake a year over the last century, making sure it’s earthquake-proof it’s just a priority – it’s a necessity.
So how do you shield what was once the tallest building in the world from Taiwan’s frequent enough devastating earthquakes?
You build the world’s largest tuned mass damper.
From what I understand, the basic idea behind a tuned mass damper is that it sits inside a structure and if that structure moves, seeks to counter the shift in weight that results and prevent collapse of the housing structure.
Due to the sheer size of Taipei 101 and the frequency of earthquakes the country experiences, needless to say the damper found in Taipei 101 is currently the largest tuned mass damper in the world.
Looking like something out of a Lego set, the Taipei 101 damper is
- the first observable tuned mass damper in the world
- weighs 660 metric tons
- 5.5 metres in diameter
- built from 41 circular steel plates welded together
- designed to reduce Taipei 101′s swaying by up to 40% during which the damper is capable of swinging 150cm horizontally
Situated on the 87th floor inside 101, the tuned mass damper is anchored from the 92nd floor by 8 high strength steel cables.
These cables are 9cm in diameter and consist of more than 2,000 wire strands each.
All in all, Taipei 101′s tuned mass damper is quite the impressive bit of hardware I’m sure you’ll agree. Coming in at a cost of $4 million USD though, surely they could have got a better paint job…
Truly looking like a giant Lego Death Star, 101′s damper is sorely crying out for a dark grey detailed paint job.
As ghastly as bright yellow looks… I suppose at least it’s not plastered in Hello Kitty pink. Although knowing Taiwan, no doubt a bright pink color scheme ran a close second.
December 22nd, 2011 at 5:37 pm TaiwanTeacher(Quote)
I wanna go for a ride! How long do you think I’ll have to sit on that damper until a BIG earthquake arrives? While waiting, will you bring me some sandwiches?
Oh well…. No time for such frivolities right now; I’m off to broker the sale of an F-5 jet.
Merry Christmas!
December 22nd, 2011 at 7:23 pm ausGeoff(Quote)
There’s a little animation here of how these things work…
http://en.wikipedia.org/wiki/Tuned_mass_damper
December 22nd, 2011 at 9:36 pm ozsoapbox(Quote)
Yeah saw that when I was doing my research. Reckon it’d be interesting to be there right when an earthquake strikes. One in a million (or more?) shot though
.
December 23rd, 2011 at 6:32 am TaiwanTeacher(Quote)
The thought of straddling that sphere and riding out an eathquake inspires me to sing my recently found Karaoke song, “I’m on the top of the world…” Do you think the damper could stay with the beat?
December 27th, 2011 at 8:08 pm Klaus(Quote)
When I talked to the 101 management once for an article I was writing, they told me the damper is actually there to shield the building in case of typhoons, not earthquakes.
December 28th, 2011 at 1:58 pm ozsoapbox(Quote)
Dunno, I’d have thought the swaying from an earthquake would be much more damaging then from a typhoon.
That and earthquakes would be much more likely to occur no?
December 29th, 2011 at 9:47 pm TaiwanTeacher(Quote)
I wonder if the damper was there when the earthquake hit Taipei 101 during its construction, killing five people.
http://www.youtube.com/watch?v=4ZNTaH2-oE0
http://gizmodo.com/5019046/how-a-730+ton-ball-kept-the-second-tallest-building-from-falling-during-the-chinese-earthquake
December 30th, 2011 at 12:52 am ausGeoff(Quote)
Wind loading can be just as destructive as earthquakes…
And although it sounds counter-intuitive, the taller a building is, the more resistant it is to earthquake damage.
Which means that during an earthquake, you’re actually safer in a 101-storey building than a 5-storey building. Skyscrapers have inbuilt sway engineered into their structural components; low-rise buildings can’t sway, and therefore are more likely to collapse during an earthquake due to their inherent structural “stiffness”.
December 30th, 2011 at 2:50 am TaiwanTeacher(Quote)
@ausGeoff – Spoken like a true structural engineer!
I agree. That’s why I live on the top floor of a nine story apartment building on the coast that has held up for 28 years of earthquakes and typhoons… IN HUALIEN!
December 30th, 2011 at 12:29 pm ozsoapbox(Quote)
Hmm, I’ve felt the sway on a 20+ story building during strong winds here… it’s freaking unnverving at times (the rolling tilt in the ground really throws you off).
I think I’ll stick to the lower highrises
. If they start to collapse I can always jump out the window and hope for the best!
December 30th, 2011 at 5:31 pm ausGeoff(Quote)
I’m only guessing, but I’d say that the “Taipei 101″ would be swaying at around 1,000mm in each direction at its top…
The rule of thumb for tall buildings is that the amount of sway (or more correctly, horizontal deflection) is its height divided by 500. So at around 450 metres this gives a very rough figure of around 900mm.
The architectural shape also has to be considered, as high winds produce swirling of the air, or vortices, at the building’s surfaces. If those wind vortices break off the building in an organized, rhythmic fashion, the sway will be increased.
If you can have these vortices break off at random or unorganized points in time, you can reduce this resonance.
That’s possibly why the Taipei 101 has those “steps” in its facade, and the returns built into its corners, as per this image:
http://img47.imageshack.us/img47/8664/taipei101day9ye.jpg