Buildings in Earthquakes: Why do some fall and others don't? (educational)

www.iris.edu/earthquake for more animations
All buildings have a natural, period, or resonance, which is the number of seconds it takes for the building to naturally vibrate back and forth. The ground also has a specific resonant frequency. Hard bedrock has higher frequencies softer sediments. If the period of ground motion matches the natural resonance of a building, it will undergo the largest oscillations possible and suffer the greatest damage.
Dr. Robert Butler (Univ.Portland) gives demonstration of resonance.
Animation & graphics by Jenda Johnson, Earth Sciences Animated
Video demonstration by Dr. Robert Butler, University of Portland
Narrated by NappyT
Guitar solo by Dennis P. McNamara
Science editing by Dr. Robert Lillie (Oregon State University) and John Taber

[@Ciubowski]

This video deserves more views.

[@extraterrestrial7424]

Very well made video. Thanks to it, I learned that structures have a natural resonance frequency and how big of a difference it can make.

[@marcidorman]

Great video! Explanation, graphics, and demo were all very clear. Shared with my family (3 generations) and everyone found it interesting. I love being able to better understand why some types of building are devastated by an earthquake while others remained standing.

[@kytddjj]

.

[@aashishp007]

The explanation has clarified all my doubts...Thanks a ton!!!!

[@mvdmusicvideostorefreshthe3224]

On the Tacoma's Narrow bridge something called 'Vortex Shedding' added to the problem. I love this video though, so thank you for providing it.

[@ngwilliam5619]

Very clear demonstrations. Thx

[@NK-iy6if]

God bless you ! Thank you so much the video has been incredibly helpful.

[@valeriewedel2775]

Awesome video - thanks! Bringing this to my commercial construction drawing class.

[@haominghuang4990]

phenomenal, informative video

[@wpegley]

Great video & thx.

[@gehadyasser1001]

Super clear thnkss a lot

[@simantsoren1120]

I've learned a lot thanks

[@handedilhan]

Thank you

[@AndrewNowacki]

Great video.

[@ranjithalluri604]

Excellent

[@anjalisuresh8896]

Very helpful video

[@satishvenkata1214]

SUPERB SIR

[@mahendarreddy9862]

Very nice video

[@eeesss9593]

great great great one.

[@deepakchacko5585]

Superb

[@fps8093]

wow amazing

[@priyanshupatel2282]

GREAT

[@SunandGold]

Thank you!!!!

[@liboy9844]

But not much help if it boils down to luck on which building you’re in and what type of earthquake occurs.

[@deemarrero9]

Amazing video, well explained and graphics.. very important to know this, since with all the damages Human Race it's been doing to mother earth 🌍 Earthquakes like those in Turkish it will happening more frequently in the whole word.

[@captain6198]

Doesn't the frequency & its amplitude change according to the size of the earthquake? Surely that ground & building structure plays a key role in general durability against collapses, but what about the shockwaves? Surely a magnitude & destruction power of say 5.5 and 7.4 earthquakes can't be the same, also depth is another factor.

[@mariannamakari9593]

They also change according to the types of soil that the wave meets on its way from the epicenter to the structure.

[@altaistein]

Who is here watching this video after the earthquakes in Turkey?

[@itziamejia1360]

what would be the equation of resonance?

[@danielsmb2635]

It is the eigen value of the system; in this case the building system consisting of mass and stiffness…

[@kobidkunwar627]

Thanks

[@RC-RCdesignstudio]

The most earthquake-resistant house in Japan is a wall-type RC house.

[@georgen9755]

crest to crest ..period ≤1 sec

[@georgen9755]

ex. Japan 2011 capital e

[@georgen9755]

one wave cycle equals twenty one Hertz

[@TheOtherSideBooks]

who's here after the Ny Earthquake

[@chandradeepraut9306]

I wanna be civil engineer