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Tuned Mass Damper of Taipei 101

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Re: Tuned Mass Damper of Taipei 101

#61

Post by brenainn »

brenainn wrote: post #47
luobogao wrote: post #39

Earlier quoted context omitted.

Actually Taipei was only around 2. Magnitudes 6-7 were in the epicenter near Taitung, fairly far away - about 200-300km.

Lots of factors affect how an earthquake is felt, so you're better off looking at peak ground acceleration and the Modified Mercalli intensity scale. https://earthquake.usgs.gov/earthquakes/eventpage/us7000i90q... You can see on the shakemap Taipei has an MMI of close to 4, which corresponds to: "Felt indoors by many, outdoors by few during the day: At night, some are awakened. Dishes, windows, and doors are disturbe…

Coming back to this I understand now you were referring to Taiwan's own intensity scale and not some recalculated magnitude - my bad! Wanted to clear up that I wasn't dunking on Taiwan's measurements. Their own intensity scale is likely better tuned for the region.

Re: Tuned Mass Damper of Taipei 101

#63

Post by Beldin »

saryant wrote: post #31
chiph wrote: post #6

The shape/design was copied by the Westworld designers for the quantum supercomputer "Rehoboam" in season 3. https://www.youtube.com/watch?v=TgBtBkW0u8Y Also - given the large motion of the damper in today's earthquake, why weren't more people freaking out? I'm also curious about how much the dampers (shock absorbers) heated up from restraining the movement of the ball.

I was on the ground floor of a modern building in Tokyo when Fukushima happened and barely felt a thing. These systems are remarkably effective.

I would not expect this system to have any effect on shaking at ground floor level - it's meant to counteract sway, which at ground floor should be zero.

Re: Tuned Mass Damper of Taipei 101

#64

Post by xucheng »

luobogao wrote: post #39
graderjs wrote: post #24

Earlier quoted context omitted.

It was actually a 6.9 https://earthquake.usgs.gov/earthquakes/eventpage/us7000i90q...

Actually Taipei was only around 2. Magnitudes 6-7 were in the epicenter near Taitung, fairly far away - about 200-300km.

You are confusing two different units. The earthquake moment magnitude scale measures the amount of energy of a given earthquake. It does not concern the location you are and the shacking you felt. Therefore, for this particular Taiwan earthquake, its magnitude is 6.9 regardless of the location.

The intensity scale on the other hand measures the amount of shaking for a given location. Naturally, the further you are from the epicenter, the lower the intensity will be.

Re: Tuned Mass Damper of Taipei 101

#66

Post by strainer »

max51 wrote: post #36

Passive mass dampers are used for wind, not earthquakes. their performance for earthquake is so bad that researchers don't even bother studying it. If you use google scholars, the only results you get are researchers mentioning in their intro that passive systems don't work for seismic and then they propose an active (ei. with motors, pumps, etc.) system or a semi-active system (ef. fluid dampers with electronically…

How about the mass dampers in thousand year old Japanese pagoda architecture ?

https://www.electronicsweekly.com/blogs/engineer-in-wonderla...

Re: Tuned Mass Damper of Taipei 101

#67

Post by graderjs »

daiamid wrote: post #57
graderjs wrote: post #24

Earlier quoted context omitted.

It was actually a 6.9 https://earthquake.usgs.gov/earthquakes/eventpage/us7000i90q...

Taiwan uses Richter magnitude, USGS uses Moment magnitude. 6.8 and 6.9 are both right, just different unit.

Alright, fine. Thanks for educating me. I was wondering about this quite a lot: some places, like USGS said 6.9, while some news articles said 6.8.

Also, another thing: why does an earthquake often have an initial magnitude that then changes over time? Like I think the initial ping for this was a 7.2, like take a look at this prelim from USGS:

https://twitter.com/USGSted/status/1571394895075500032

How can it be OoM off at first?

Re: Tuned Mass Damper of Taipei 101

#68

Post by graderjs »

alisonatwork wrote: post #53
luobogao wrote: post #39

Earlier quoted context omitted.

Actually Taipei was only around 2. Magnitudes 6-7 were in the epicenter near Taitung, fairly far away - about 200-300km.

There seems to be a bit of confusion in this thread between differing seismic scales. The Central Weather Bureau in Taiwan uses an intensity scale where a value of 2 means the event is noticeable by most people and 3 means some of those people are frightened.[0] For example, here[1] is the recent report for this morning's "5-" event (#137), which I can assure you everybody in the office still felt in Taipei, where it…

This is great, thanks! :) ;p xx ;p

Re: Tuned Mass Damper of Taipei 101

#69

Post by graderjs »

brenainn wrote: post #61
brenainn wrote: post #47

Earlier quoted context omitted.

Lots of factors affect how an earthquake is felt, so you're better off looking at peak ground acceleration and the Modified Mercalli intensity scale. https://earthquake.usgs.gov/earthquakes/eventpage/us7000i90q... You can see on the shakemap Taipei has an MMI of close to 4, which corresponds to: "Felt indoors by many, outdoors by few during the day: At night, some are awakened. Dishes, windows, and doors are disturbe…

Coming back to this I understand now you were referring to Taiwan's own intensity scale and not some recalculated magnitude - my bad! Wanted to clear up that I wasn't dunking on Taiwan's measurements. Their own intensity scale is likely better tuned for the region.

This is all, awesome. Thanks! I did not know a lot of these details! :) ;p xx ;p

Re: Tuned Mass Damper of Taipei 101

#70

Post by graderjs »

xucheng wrote: post #64
luobogao wrote: post #39

Earlier quoted context omitted.

Actually Taipei was only around 2. Magnitudes 6-7 were in the epicenter near Taitung, fairly far away - about 200-300km.

You are confusing two different units. The earthquake moment magnitude scale measures the amount of energy of a given earthquake. It does not concern the location you are and the shacking you felt. Therefore, for this particular Taiwan earthquake, its magnitude is 6.9 regardless of the location. The intensity scale on the other hand measures the amount of shaking for a given location. Naturally, the further you are f…

Thank you, this is good! :P :) xx ;p

It's quite confusing to have a couple of different numbers to "characterize" a quake: magnitude (in a few different systems), intensity scale (guess there are different systems around the world as well).

Really great to see the clarity here from knowledgable people on this! :) ;pxx ;p

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