Which Buildings are Safe in an Earthquake?

Earthquakes can be so destructive to structures and societies. This video explains what we have learned about them and how engineers deal with the enormous seismic forces. The key concept in seismic design is to allow damage to be sustained by the structure. The cracking of concrete, yielding of steel, or snapping of bolts and fasteners requires input energy. This energy comes from the earthquake and is dissipated when the damage occurs.
However, if the structure is not designed properly this damage could cause a complete collapse. Therefore, it is crucial to provide a ductile design that could sustain a lot of damage before the structure loses its capacity to maintain its gravity loads.
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Content references:
[1] R. Villaverde, Fundamentals of Earthquake Engineering, London: CRC Press, 2009.
[2] Structural Engineering Institute, ASCE 7: Minimum Design Loads for Buildings and Other Structures, Reston: American Society of Civil Engineers, 2003.
[3] A. K. Chopra, Dynamics of Structures, Prentice Hall, 2012.
[4] Encyclopaedia Britannica, "Encyclopedia Britannica," Britannica, 12 8 2021. [Online]. Available: www.britannica.com/event/San-.... [Accessed 27 September 2021].
[5] Wikipedia, "Great Hanshin earthquake," Wikipedia, [Online]. Available: en.wikipedia.org/wiki/Great_H.... [Accessed 15 September 2021].
[6] A. R. Kolbe, R. A. Hutson, H. S. E. Trzcinski, B. Miles, N. Levitz, M. Puccio, L. James, J. R. Noel and R. Muggah, "Mortality, crime and access to basic needs before and after the Haiti earthquake: a random survey of Port-au-Prince households," Medicine, Conflict and Survival, vol. 4, no. 26, pp. 281-297, 2010.
[7] European Committee for Standardization, Eurocode 8: Design of structures for earthquake resistance - Part 1: General rules, seismic actions and rules for buildings, European Committee for Standardization, 2004.

[@waynepetrevan]

here is your title: Which Buildings are Safe in an Earthquake?. Its an interesting video but I don't think you anwered the question.

[@TheEngineeringHub]

It's hard to answer because it's dependent on many factors amongst which the earthquake itself too. In general, taller buildings tend to perform better because they oscillate at frequencies different than the frequency of the earthquake. Earthquakes shake rapidly i.e. the direction of acceleration (shake) changes every 0 - 3 seconds. Tall structures shake slowly 3+ seconds to complete 1 full cycle. For that reason the shaking of tall structures does not usually coincide with the shaking of the earthquake which means less energy is transferred to the structure and therefore less damage is sustained. This is the simple answer but of course it needs like 10 footnotes for all the possible exceptions and cases where this is not the case. I hope that helps? Cheers!

[@waynepetrevan]

@@TheEngineeringHub it would be interesting if you were to do a similar video showing/explaining why there has been so much damage recently in Turkey. Considering that it has been fairly common knowledge that Turkey has been waiting for big earthquakes for years, there have been many predictions about it being only a matter of time(Istanbul for example). Why then would they not build accordingly?

[@mehmettemel8725]

@@waynepetrevan The answer to that lies largely on builders who have been cutting corners and not building the structures as per engineers design and the corrupt local council employees turning a blind eye receiving bribes from builders.To top it all off governments didn't enforce the rules and punish those responsible for decades and now after it's too late some have been convicted which won't bring the dead back.After the big earthquake in 1999 new laws were passed regarding new building regulations where some were adhered by some builders and as we saw others haven't even though there was a lot of collapsed buildings relatively new.

[@jasontempest4233]

In Christchurch NZ nearly all the buildings remained standing, maintaining their gravity loads, and yet had to be demolished later resulting in vast areas of the city being empty.

[@Sashazur]

It means that engineers correctly designed the buildings to save lives. That’s the most important thing, but once you have an entire city built like that, after a big quake there’s a huge economic loss - not just because buildings cannot be used and must be replaced, but also because economic activity simply moves away to undamaged areas. Once that happens it may take years to come back. Although it’s impractical to build to withstand any quake, spending more to improve the chances that the building will be more likely to be usable or repairable after a quake may make sense.

[@Aunestly]

@@Sashazur wow never thought about that way smh.

[@akanshajain9731]

​@@SashazurI couldn't get 🤔. What do you mean? 🧐

[@vignarajahkm4462]

Enjoyed your videos. Please keep up the good work!

[@Morganasnotarobot0]

RiteOn!keepUp the Good Work! With grateful thanks! 🙏

[@JJustMax]

A pretty relevant video for february 2023

[@vesnastamenova3339]

So good! Thanks for the video, please keep going!

[@TheEngineeringHub]

More to come!

[@sabircek]

Great job, thank you for your effort

[@SpiderCollector000]

In the 1994 Northridge quake, peak acceleration in some areas was as much as 2 G's caused by a blind thrust fault with severe up/down motion, and the San Andreas fault snapping with a Magnitude 8 is expected to create a more rolling and side to side shaking with up to 2 G's, but that kind of quake would shake easily for 75 to 90 seconds, if not more.

[@ravshanbekmavlonov2996]

My brain is filling with your very important videos! Thanks!

[@TheEngineeringHub]

We are happy to see you working your way through 3 of our videos Mavlonov. We love it when viewers come back for more! 🙏

[@Morganasnotarobot0]

​@@TheEngineeringHub look forward to More Interesting Videos &🤍Sub!👍

[@ajazmahemoodsayyed4122]

Amazing sir

[@nikoletakonstantaki5068]

Wow so good!

[@TheEngineeringHub]

We are happy to know that you enjoyed the video 😊

[@rubentuting525]

pls do more videos about designing an smrf structures

[@satishreddy1958]

Your videos are the best... 1 video is equal to 10 classes at the college... Thank you...

[@xl000]

Which college did you attend...

[@malsawmtluangakc2396]

Please make a video about the pros and cons of corner bracing in reinforced concrete structures? Just as Ross Stein suggested in his video in tedtalk

[@TheEngineeringHub]

That's an amazing idea Malsawmtluanga, it has been added to the future videos list! Thank you!

[@Morganasnotarobot0]

​@@TheEngineeringHub thank you!Subbed!🙌

[@ChristianWagner888]

The corner bracing was an interesting point in Ross Stein's video. This would be especially relevant for retrofitting "soft first story" buildings. There are other methods of bracing or stiffening available as seen especially in Japanese earthquake engineering. Infill walls or shear walls act as bracing as well. In all cases of bracing, you also don't want the building to become overly stiff. The columns need to be stronger than the braces or infill walls, otherwise the bracing could do more harm than good. Also a stiffer building has a shorter resonant frequency, which may not be desirable. The bracing needs to be engineered well to maintain sufficient ductility. It's all a bit more complicated than the explanation in the Ted talk.

[@nestorleconaramirez9296]

Keep going! Your content is really good.

[@TheEngineeringHub]

Thank you Nestor. Reading comments like this always gives us extra motivation and will to keep going! 🙏

[@vexelat4361]

The most important thing is the soil that they skipped , literally the 70 percent of a seismic event’s importance is the soil

[@SlytigerSurvival]

Good video

[@TheEngineeringHub]

Thanks for the visit

[@santoshkumar9605]

Are flat slab construction advisable in high seismic zone.?

[@stephenbohnsack9304]

Enjoying the material from a carpenter here.

[@ginelle7213]

These high buildings are like traps to us during earthquakes occur in regions of earthquake zone. Therefore we should construct an earthquake proof building .

[@macberg5806]

There’s no such thing. All buildings will get damaged in an earthquake. Even an “earthquake proof” one. The cost involved to make a building fully quake proof likely isn’t practical. The most important thing is saving lives. Not buildings.

[@elatar83]

Disagree with you you can have build that can withstand earthquake the biggest issues are the contractor it comes down to costing. When testing is carried out the standards are to be tested in a 3/3 Furness and when a company has to carry out test they will be done for each product being used when doing testing its the time and the costing that comes into place it cost millions of pounds for testing and who will take the costing of this. No building will withstand an earthquake without having some sort of effect if it is from the foundation and piles to movement of the land.

[@jamesdellaneve9005]

@@macberg5806 Correct. They just want them to survive a big one so that people can get out alive. They also want them to remain intact on small and moderate quakes.

[@jamesdellaneve9005]

We have a joke in aerospace. “Why don’t we design the airliner like a black box, since they survive the crash”? The truth is, it would be so heavy that it couldn’t fly and even if it could, the people would be turned into hamburger after a crash.

[@kacperwoch4368]

After the Turkey earthquakes I was wondering why many tall and thin minarets, even the ancient ones build out of stone survived. It seems they have low rigidity and act as very tall skyscrapers, preventing them from collapse.

[@otgunz]

Turkiye and Syria, 2.6.2023, 70.000 counted a rising after 2 weeks of rubble digging. 7.8 and 7.6 (9 hours later). The total population living 100km and closer to the fault line 14M. 90% of buildings were concrete-iron built, in avreaga 3-11 stories, most were built without regulations or with very old regulations making the structures built much weaker to stand still against a 7.8 shock. Yet msot of the never buildings on the dangerous proximity also collapsed. 14000 buildings totally collapsed for 14M population. Difference between Japanese faults and Anatolian is that, although Japanese faults create 8-9 magnitude earthquakes, they are deep in the ocean, and 30-100km deep into the earth, making the actual destructive force emitted already and reduced until it reaches the cities on Japanese islands. Yet the shake will be there non the less. In Anatolia, cities are built on or very near of faults. And the faults are only 7-15km deep into the earth. So much more closer to the residental area. Therefore a 7.8 magnitude 10km from your location and 10km into the earth makes a destruction much heavier than a 9.2 magnitude 200km away from you, 70km inside the earth. Still, death is death, science is science, if built right on the right place, even if close to the fault, buildings survive the hit at least as good as you can leave the building afterwards. Collapse means the buildings are built wrong to fight the earthquake shock. Therefore Turkish and Syrian engineers, contractors, controllers and local governments who are responsible for the permits of building locations for geological structures and safety are to be blamed for all the deaths.

[@Morganasnotarobot0]

Thank you! It shows how Earthquakes Are Powerful Siesmic force, that All Best Professional Highly Great Talented Architects Engineers Engineering Must Be Of KeyQualityValue! Including Excellent Materials!to Withstand Highly All it's force!from these Heartbreaking sad Catastrophes! Prayers 🙌🙏🙌 for All dear Ones🙏 that have been, Are sadly devastingly effected! May All the Best Engineers Bring More Solid Safety BEAUTY And Valuable insights Your commentary is Most Special in trying to Understand These Vital Needs. For the Best Of All GREAT ❤️

[@wacky6136]

What is the difference between "gravity load" and 'dead load"? Thanks for the video. Very well done video.

[@TheEngineeringHub]

Hi wacky, thank you for your feedback. Dead load is a type of gravity load. Besides dead loads, there are also live loads, snow loads, etc that fall under this category of masses accelerated by gravity.

[@bashirahmadrasheedy1081]

Gravity Load and Dead Load are the same bro! Gravity Load is common exist every where, but the dead load is specific name for the gravity load specially when it uses on structure. I may be wrong. thanks

[@emmabird9745]

Gravity loads are loads which act downwards due to the weight (more correctly mass) of items including the structure. Dead loads are those gravity loads which do not move ie are fixed. The weight of the structure itself and any items fixed to it. Counter intuitively snow load and occupant load can be considered dead load. Gravity loads include live loads which are due to moving masses eg the lorry (truck) on a bridge.

[@josephpagala1590]

Dead load is part of gravity load.

[@21stcenturyentertainment14]

For a 8m tall 2 storied building we have only 20*40cm column cross section. Any idea to make this long column strong💙

[@RR-ho3td]

How is it that a 2 storey building is only 5m? I think it should at least be at 8m.

[@21stcenturyentertainment14]

@@RR-ho3td ys typing mistake its 5m gound + 3 m first floor

[@Aranimda]

Lego structures are fairly well earthquake proof. Maybe we should lean by looking at the characteristics of the lego system as building material.

[@PacoOtis]

Thanks for sharing! The intrusive music is distractive and you might ponder not using it. Best of luck!

[@candicewitzkoske3155]

A house built on sand cannot stand…..

[@tafadzwamusekiwa659]

Need a mentor please

[@Rhino011]

you forgot Mexico City in the 1980s.

[@monirelhanafy9606]

In the name of Allah, the Beneficent, the Merciful.[15:22] And We send the winds fertilising, and cause water to descend from the sky, and give it you to drink. It is not ye who are the holders of the store thereof.

[@otgunz]

bulls****. Quran says Allah put mountains to prevent earthquakes. Yet science says mountains created by the movement and crash of plates via earthquakes. Thus mountains are a solution not a necessity. Quran died long before man died on this planet. 1400 years of science was enough to debunk a book that claims it hold the knowledge of 13.8 billion years of creation. There might be a god or no god but Allah is not "the" god for sure.