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How We Design Buildings To Survive Earthquakes

How We Design Buildings To Survive Earthquakes

DNews is based in grand old San Francisco.
Known for it’s culture, or counterculture, giant reddish orange bridge, and earthquakes. Earthquakes happen when tectonic plates shift.
This sudden burst of energy sends seismic waves shooting in all directions. These waves
can violently shake buildings both up and down and side to side with enormous force.
It’s this forceful shifting that actually causes stress on the buildings to the point
of collapse. As we live in an Earthquake prone area, we
realize a fundamental truth. Earthquakes don’t kill people. Buildings do. So researchers
have spent a lot of time wondering how to make buildings safer. When an engineer is first planning a new building
they have to take into account where the building will be built. Earthquake guidelines are different
in say Kansas than in California. The intensity of forces from Earthquakes varies from place
to place. The goal when building in high intensity earthquake
areas is to make a building earthquake resistant. Earthquake proof is doable, but extremely
expensive. Now, to be considered “Earthquake resistant” a building can suffer damaging,
but it can’t collapse on the people trying to get out. And there’s two main ways to
do that, by designing a building so it’s stronger or more flexible. One way engineers
can make buildings stronger is by reinforcing concrete with steel. But in high risk areas
like California, that’s often not enough. One of the most effective ways to protect
a building from such disasters is to keep them from moving by detaching it from the
ground. Base isolation is when engineers design a structure to be built on top of a separate
base, instead of attached to a foundation, so that when an earthquake hits, the base
moves, but the building only ways slightly. For instance San Francisco’s City Hall was
retrofitted with a base isolation system. And this concept isn’t new. We see these
examples as early as the 4th century. They utilized isolation bases made of smooth rocks
that could slide against each other. In modern times these bases are usually made out of
a combination of a flexible material like rubber and steel. The rubber also acts like
a shock absorber. But a cool piece of shocking tech comes Taiwan.
The supertall skyscraper, Taipei 101, combats earthquakes with a giant 728 ton ball. Well
it’s technically called a “tuned mass damper” but it’s basically a giant ball
that’s suspended near the top of the building. If the building sways because of an earthquake
or a typhoon, the damper swings in the opposite direction. During a particularly strong gust
in 2015, the ball in Taipei 101, swung a meter from it’s center position. And technology is getting even more advanced.
According to one study published in the journal Applied Physics Letters researchers are working
on a way to make a building invisible to shock waves using a shield. This shield of concrete
and plastic buried at least 3 feet down, looks like two rainbows surrounding the building
with a gap between them. Each strip, or “color” is more stiff the farther out they are from
the core. The waves have an easier time traveling through a stiff and hard layer. So the waves,
once they hit a softer layer, deflect and head back to the easier path. The way these
plates curve, essentially channels the shock waves around the building. As they move around
the building they hit a gap in the plate which allows some of the force to dissipate. So
the plate kind of hides the building from the Earthquake. Like an invisibility cloak
for earthquakes! When earthquakes hit, their intensity is measured
in a point system called the richter scale. Trace takes a look at the different ways seismologists
measure earthquakes and what do these ratings mean in this episode right here. Have you lived through an earthquake? Tell
me your experience down in the comments below

100 thoughts on “How We Design Buildings To Survive Earthquakes”

  1. 1985 a very strong earthquake destroyed Mexico city, I was too little don't remember anything but a few 7 grade earthquakes didn't scare me of all till one got me in a big building that was chasing really bad and turn very noisy, that was pretty scary

  2. Really? Not even a mention about Japan or Chile? Even there's a special way of contruction called Chilean Ingeniery? California can't even produce an earthquake over 8.0

  3. survival of 2005 Kashmir earthquake here.

    Now i live in geographical area with no risk of deadly natural disaster

  4. I remember living an earthquake, about 7 Richter scale, I was on a hospital in shape of tower and the building was relatively old, that was quite an experience, but at the end I remember that made me to assure myself on studying engineering, I remember seeing the engineers checking the building after the earthquake that made it all.

  5. Survived a 4.8 earthquake in B.C. lower mainland in Canadw, back in December 2015.. Was scary, but pretty cool. It took me a few second to realize it was an earthquake.. but by then it was already over. So I guess the "thing" about people taking time realizing what's going on, indeed is true! Happened to me and my family!

  6. I experienced my first earthquake in Virginia back in '11. It wasn't very big, but since I had never felt one before, it was pretty surprising and quite frightening, to be honest.

  7. I was in Tokyo during the 2011 Tohoku earthqualke. The floor of the house was swaying for about 30 seconds. Since I was in Japan the immediate danger was falling object from shelves, therefore hiding under the table was the safest measure to take.
    Also I had prevention earthquake training so I knew what to do during and after the earthquake.

  8. I live in California. The last earthquake that I can remember being more noteworthy than others caused a reaction in my family and I resembling contempt. I remember my dad looking at me and saying "well, I guess we better step outside real quick."

  9. I've survived two earthquakes, 27 Feb, 2010 in Chile it was 8.8 but I was sleeping and didn't feel most of it, only the last 20 seconds, it was intense.

    The second one, September 2015, 8.3 in Illapel, I was at Pizza Hut with a friend and my cousin and we just bought a pizza, we were waiting for it outside and suddenly we thought that my cousin was moving the table but it was an earthquake and all the Pizza Hut workers ran away, we didn't move and we waited for 30 minutes, they came back and gave us the pizza, and they still made us pay after making us wait that long.

  10. Almost every major building (+3 storeys) in Chile is build with reinforced concrete and homes have reinforced concrete beams and pillars, we are a 3rd word country and for our standards is not expensive at all, it's just one of the safest ways to build.

  11. I'm from New Zealand. I live next to a fault line. I don't have an emergency kit. We get so used to living in an area like this that we just don't really care.

  12. I experienced once, just last month 2016. We were having a quiz in our major subject (3rd floor building) when suddenly I felt my chair moved. I thought that my classmate at the back just kicked my chair so I just continued answering the quiz. Then, one of my classmates at the front turned and asked me if I kicked her chair xD. One of my classmates said "Guys! There was an earthquake!".."Really?" "No, we just moved all together" ….Nah, we just continued our quiz. After that class, we looked at twitter and news page, yes, there was an earthquake.

  13. I didn't live through an earthquake, but my mother did in her homeland of Guatemala.She explained that there was a brick wall about to tip over and flatten her. For some miraculous reason, it ended tipping and falling the opposite way which enabled her to survive the earthquake. And she went to have me after. She is a warrior and defied death and unbelievable amount of times (including a series of strokes a month before hurricane Sandy [we resided in Long Island, NY at the time]). She passed away this past October. I miss her.

  14. I live in Indonesia and I've experienced so many earthquakes, including the biggest one in May 2006 which kills about 5,000 people. The damage that is done by the earthquake depends on the depth of the epicenter too, in which the 2006 earthquake only has 5,9 richter but the depth is only 10 km or something.

  15. As a Chilean, the scariest part of an earthquake is not knowing beforehand if the building you're in in earthquake resistant. It's usually the case, but you often have no way of knowing.

  16. I did live through one it was a 7.4 in CA and I shot my TV off its base but that's th only thing that broke I'm glad my legos didn't break

  17. Does anyone know what's the technical name of the "earthquake shield" mention in the time 2:45 ?? I'm interested to read more about it.

  18. I had experienced an earthquake when I was 9 years old. I was outside playing with my cousin and the ground shook for 5 seconds. It was a minor earthquake though.

  19. I have never been in an earthquake. Buildings need to be built stronger and more stable because earthquakes don't kill people, buildings do.

  20. It was Christmas Eve.

    It was in Puerto Rico, back in 2010 when my mom was recovering after having a kidney removal surgery. I was at a Christmas party with my grandparents and family.

    We were having a great time and partying with the parranda. Until the quake shook the mountains.

    To be honest, it wasn’t that big, it was about a 3.2. Though I did sleep over another earthquake that was at most a 5.5. And some aftershocks that were minor.

    The only damage that was done after the quake was my moms sanity.

  21. There is my invention … Tensioning between of the upper edge of the walls with the earth reduces the displacements responsible for all the stresses that develop on the structural carrier.
    The patent is stacked into the ground to draw from it a force that transfers it to the upper end of the wall in order to apply a counterbalance to the torque of the wall Τhe patent achieves the following
    1)The consolidation of the nodes of highest level of the walls with the ground, using the mechanism of the invention, deflects the upward tensions created by the wall overturning torque transporting them freely and directly from the roof into the ground and in this way stops the displacements responsible for all growing tensions on the body of the bearing elements which they cause inelastic bending deformations and failures in a major earthquake. 2 ) Also the mechanism and method of anchoring provides very strong foundation in soft soils 3)The wall receives only compressive stresses at both ends a) at the upper end b) and the facing lower end near the base. Does not exist anymore tensile strength. This means that there are no longer torques in the nodes Does not exist anymore mechanism of concentric forces failure The floor mechanism (soft floor) does not exist anymore 4) Does not exist anymore coordination because the whole construction is shifted with the same frequency and the same oscillation amplitude 5) The wall also receives horizontal shear forces. Apply tension at all edges of the wall with the patent mechanism increases the ability to horizontal shear forces.

  22. Even if I am not a civil engineer, I will do press subscribe to see your beautiful eyes all the time in spite of I do not understand what you are talking about haha

  23. i think they should leave there because it is not safe there on the internet it said that is is go to be there but i think it is no safe

  24. men have been betterizing buildings all our lives.  Hats off to the men that build our world!

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