Can We Make Buildings Truly Earthquake-Proof?

Summary

This SciShow episode explores innovative engineering solutions to protect buildings from earthquakes. It discusses current methods like tuned mass dampers in skyscrapers and shock absorbers using rubber and lead. The show also previews upcoming technologies, including vibrating barriers that absorb vibrational energy and 3D-printed cement structures inspired by nature's resilience. Additionally, the concept of 'earthquake invisibility cloaks' that use rings to deflect seismic energy is introduced, highlighting the potential for future earthquake-resistant architecture.

Takeaways

• 🌏 Earthquakes are currently impossible to predict with certainty, necessitating constant vigilance in areas prone to seismic activity.
• 🏢 Engineers have developed various technologies to protect buildings during earthquakes, such as tuned mass dampers and shock absorbers.
• 🏙️ Tuned mass dampers, like the one in Taipei 101, use massive pendulums to counteract building sway, while shorter buildings often use base isolation systems.
• 🔧 Base isolation systems, exemplified by a major airport in Turkey, can reduce earthquake-induced movement by up to 80% using rubber and lead.
• 🔬 Engineers are researching advanced technologies like vibrating barriers, which use weights and springs to absorb vibrational energy and protect buildings.
• 🏛️ Vibrating barriers could be particularly useful for historical landmarks that cannot be modified, although they require specific calibration for each building.
• 🏗️ Research is also being conducted on strengthening building materials themselves, such as using carbon nanotubes or 3D-printed cement paste with specific patterns.
• 🦂 Nature-inspired designs, like the mantis shrimp's claw, are being incorporated into construction to minimize damage by distributing pressure and preventing cracks.
• 🧿 The concept of 'earthquake invisibility cloaks' involves plastic rings in building foundations that absorb and deflect seismic energy, making the building 'invisible' to earthquakes.
• 📚 For further learning on engineering challenges, including earthquakes and infrastructure, the Physics of the Everyday course from Brilliant offers in-depth information and interactive content.

Q & A

Why are earthquakes difficult to predict?

Earthquakes are difficult to predict because they are basically impossible to forecast with any real certainty, making it challenging for scientists to anticipate when the next significant earthquake will occur.

What is a tuned mass damper and how does it help in earthquake protection?

A tuned mass damper is a large pendulum placed high inside buildings, often skyscrapers, that swings in response to the building's movements. It counteracts external forces, reducing the side-to-side shaking during an earthquake.

Which famous building utilizes a tuned mass damper?

Taipei 101 in Taiwan is a famous building that uses a tuned mass damper to protect against earthquakes.

How do engineers protect shorter buildings from earthquakes?

For shorter buildings, engineers often use a system of rubber and lead at the base to isolate the building from the ground, acting as a shock absorber to reduce the impact of an earthquake.

What is a seismic isolator and how does it work?

A seismic isolator is a device used in the foundation of buildings to reduce the impact of earthquakes. It allows the structure to move independently of the ground, thereby reducing the amount of shaking transferred to the building.

What is the vibrating barrier system proposed for earthquake protection?

The vibrating barrier system is a proposed technology that uses a weight held by springs in a buried box near a building's foundation. It absorbs vibrational energy during an earthquake, protecting the building from damage.

How can carbon nanotubes be used in earthquake-resistant construction?

Carbon nanotubes can be used as a construction ingredient to strengthen buildings against earthquakes. They can enhance the material's strength and resilience, making structures more resistant to seismic forces.

What is the inspiration behind the 'architectures' used in 3D-printed cement paste for earthquake resistance?

The 'architectures' used in 3D-printed cement paste are inspired by the natural structures found in arthropods' shells, such as the mantis shrimp's claw, which distributes pressure through specific patterns to minimize damage.

What is an earthquake invisibility cloak and how does it function?

An earthquake invisibility cloak is a concept that involves embedding a series of plastic rings into a building's foundation. These rings have specific stiffness and elasticity to absorb and deflect earthquake energy, making the building 'invisible' to the seismic waves.

How do the plastic rings in an earthquake invisibility cloak protect a building?

The plastic rings in an earthquake invisibility cloak deform and deflect the earthquake's energy along their structure, redirecting the energy around the building, thus protecting the structure and the occupants inside.

What is the significance of the center of mass being below the surface in skyscrapers?

In many skyscrapers, having the center of mass below the surface helps to stabilize the building and prevent it from toppling over during high winds or earthquakes, as it lowers the building's center of gravity.

Outlines

00:00

🏙️ Earthquake Protection Innovations

This paragraph discusses the unpredictability of earthquakes and the various methods engineers have developed to protect buildings. It highlights the use of tuned mass dampers in skyscrapers, such as the Taipei 101 in Taiwan, which employ massive pendulums to counteract building sway. For shorter buildings, engineers use a system of rubber and lead as shock absorbers, exemplified by a major airport in Turkey that uses 300 isolators to reduce side-to-side movement by 80%. The paragraph also explores new research, including the vibrating barrier system that uses weights and springs to absorb vibrational energy, and the potential for this technology to protect historical landmarks. The importance of calibrating the system to match the building's specific frequency is mentioned, as well as the potential for these systems to reduce acceleration by almost 90%.

05:05

🔬 Advancing Earthquake Resilience

The second paragraph delves into additional innovative approaches to earthquake protection. It mentions the exploration of strengthening building materials themselves, such as using carbon nanotubes. A team at Purdue has been researching 3D-printed cement paste with specific patterns inspired by the shells of arthropods, like the mantis shrimp's claw, which distributes pressure to minimize overall damage. The paragraph also introduces the concept of 'earthquake invisibility cloaks,' which use a series of plastic rings in the building's foundation to absorb and deflect seismic energy, effectively making the building 'invisible' to earthquakes. The rings can cover multiple frequencies and protect multiple buildings at once. The technology is still in development, with potential for future implementation. The paragraph concludes with a mention of the Physics of the Everyday course from Brilliant, which covers various engineering challenges, including skyscrapers and suspension bridges, and offers a discount for the first 200 annual Premium subscriptions.

Keywords

💡Earthquakes

Earthquakes are sudden shaking events caused by the release of energy in the Earth's crust, which creates seismic waves. They are unpredictable and can cause significant damage to infrastructure. In the video, earthquakes are the central theme, with discussions on how they pose a challenge to human-made structures and the various engineering solutions being developed to mitigate their impact.

💡Fault Lines

Fault lines refer to the boundaries between tectonic plates where most earthquakes occur. They are areas of the Earth's crust that are under stress due to the movement of these plates. The script mentions that populations living on or near fault lines are particularly concerned about earthquakes, as these regions are more prone to seismic activity.

💡Tuned Mass Dampers

Tuned mass dampers are large pendulum-like devices placed in tall buildings to counteract the side-to-side motion caused by earthquakes. They work by moving in opposition to the building's sway, thereby reducing its overall movement. The Taipei 101 building in Taiwan is highlighted in the script as a notable example of a structure utilizing a tuned mass damper.

💡Seismic Isolation

Seismic isolation is a technique used to protect buildings from earthquakes by isolating the structure from the ground's shaking. This is achieved using a system of rubber and lead that acts as a shock absorber. The script cites a major airport in Turkey as an example of a large seismically isolated building, which uses hundreds of isolators to significantly reduce the impact of earthquakes.

💡Vibrating Barrier

A vibrating barrier is a proposed system for earthquake protection that involves a weight held by springs and buried near a building's foundation. It absorbs vibrational energy during an earthquake, preventing it from reaching the building. The script suggests that this technology could be particularly useful for historical landmarks that cannot be modified.

💡Carbon Nanotubes

Carbon nanotubes are a type of nanoscale material known for their exceptional strength and lightweight properties. In the context of the video, they are mentioned as a potential ingredient in the construction of buildings to enhance their earthquake resistance. This highlights ongoing research into advanced materials that can improve structural integrity during seismic events.

💡3D-Printed Cement Paste

The script discusses an innovative approach where cement paste is 3D-printed into specific shapes and patterns to improve a building's response to earthquakes. These patterns, referred to as 'architectures,' are designed to direct pressure in a way that minimizes overall damage, even if some structural damage occurs.

💡Nature-Inspired Materials

Nature-inspired materials are those designed based on structures found in nature, which have evolved to withstand various environmental stresses. The video gives the example of the mantis shrimp's claw, which has a helical pattern that distributes pressure and prevents the formation of a single large crack. This pattern is being adapted in construction materials to improve earthquake resistance.

💡Earthquake Invisibility Cloak

The 'earthquake invisibility cloak' is a conceptual technology that involves embedding a series of plastic rings into a building's foundation. Each ring is designed to absorb a specific frequency of seismic waves, deflecting the energy around the building and making it seem 'invisible' to earthquakes. This concept is an example of how engineers are exploring unconventional solutions to protect structures from seismic forces.

💡Infrastructure

Infrastructure refers to the basic physical and organizational structures needed for the operation of a society or enterprise. In the video, infrastructure is mentioned in relation to the broader scope of engineering challenges, which include not only earthquake protection but also traffic management and the construction of bridges. The script encourages viewers to explore the Infrastructure chapter in the Physics of the Everyday course for a deeper understanding of these topics.

Highlights

Earthquakes are impossible to predict with certainty, making fault line populations vigilant for the next big one.

Engineers have developed inventions to help protect buildings during earthquakes.

Tuned mass dampers, like massive swinging balls, are used in skyscrapers to counteract building movements.

Taipei 101 in Taiwan is a famous building utilizing a tuned mass damper.

For shorter buildings, engineers use rubber and lead systems as shock absorbers at the base.

A major airport in Turkey uses seismic isolation with 300 isolators, reducing side-to-side movement by 80%.

Vibrating barriers, proposed in 2015, are a new system that absorbs vibrational energy like a super-strong shock absorber.

Vibrating barriers could be ideal for historical landmarks that cannot be modified.

The effectiveness of vibrating barriers requires calibration to match a building's specific frequency.

Experiments suggest vibrating barriers could reduce building acceleration by almost 90%.

Research is exploring ways to strengthen buildings themselves, such as using carbon nanotubes.

A team at Purdue has been 3D-printing cement paste into specific shapes to improve concrete's earthquake response.

Nature-inspired patterns in construction, like those found in mantis shrimp claws, are being used to minimize overall damage.

Earthquake invisibility cloaks use plastic rings in building foundations to absorb and deflect seismic energy.

Invisibility cloaks can make a building 'invisible' to earthquakes by deflecting energy around it.

The more rings in an invisibility cloak, the more frequencies of seismic waves it can cover.

The Physics of the Everyday course from Brilliant covers infrastructure, including skyscrapers and suspension bridges.

Brilliant's course offers facts, diagrams, and interactive quizzes on various topics, including skyscrapers and airplanes.

A special offer for an annual Premium subscription on Brilliant is available for the first 200 people signing up through the provided link.

Transcripts

Thanks to Brilliant for supporting this whole week of SciShow!

You can learn more at Brilliant.com/SciShow.

[ INTRO ]

Nature has an entire suite of disasters at its disposal, and some are more difficult

to predict than others.

Like earthquakes.

Earthquakes are basically impossible to predict with any real certainty,

so populations living on or near fault lines are constantly on the lookout for the next

big one.

Still, it’s not like we’re not twiddling our thumbs, just waiting for it to strike.

Engineers have already developed some pretty amazing inventions that help protect buildings

during ‘quakes, and they’re working on more.

Here’s what they have in their arsenal now, along with a sneak peek of what’s on the

horizon.

Today, there are a few main ways we try and protect buildings from earthquakes.

One is to keep buildings from shaking side to side as much as possible,

and that can be done in several ways.

Many huge skyscrapers utilize massive swinging balls, a.k.a. tuned mass dampers.

They’re large pendulums placed high inside buildings, and they sway in response to any

movements the building makes.

That counteracts whatever is happening outside.

The most famous building with one of these is probably Taipei one-oh-one in Taiwan.

For shorter buildings, engineers often choose a different route:

They isolate the base of the building from the ground using a system of rubber and lead

that serves as a shock absorber.

A major airport in Turkey uses this method,

and it’s one of the largest seismically isolated buildings in the world.

It uses three hundred separate isolators that can reduce the side to side ‘umph’ the

earthquake puts on it by eighty percent.

Which is impressive.

Still, while tuned mass dampers and shock absorbers are great, they’re not perfect.

So engineers are also exploring new options to really step up their game.

Some of this research builds off of existing ideas.

For example, in two thousand fifteen, one group proposed a new system called vibrating

barrier,

which is like a super-strong version of a regular shock absorber.

You start with a weight held in place by springs.

Then, you stick it all in a box, and bury that box near a building’s foundation.

When an earthquake comes along, the weight gets jostled around,

and in doing so absorbs the vibrational energy that would otherwise hit the building.

This kind of tech would be perfect for buildings you can’t modify,

like historical landmarks.

But it isn’t ready to go primetime yet.

You still have to calibrate the system to absorb a certain frequency, which is specific

to each building.

That’s because, depending on a building’s mass and what it’s made of,

there are going to be some frequencies that make it vibrate more than others.

So, you’d need to use springs of a specific stiffness.

More massive buildings will also need more massive dampers.

Still, models suggest this could do a lot of good: Some experiments report that this

system could reduce the amount of acceleration a building is subjected to almost ninety percent.

Also, they could protect multiple buildings at once!

So they’re totally worth researching further.

Of course, there are a thousand ways to solve a problem, so other teams have approached

this earthquake challenge a little differently.

For example, one major field of research involves investigating how to strengthen the buildings

themselves.

Some of that involves using fancy new construction ingredients, like carbon nanotubes.

But there’s another way to go about it, too.

Like, in twenty eighteen, one team at Purdue announced that they had been 3D-printing cement

paste into specific shapes and patterns to improve the concrete’s response to earthquakes.

They’re calling these patterns “architectures”, and they’re capable of carefully directing

pressure that could induce cracks.

So, even though damage does happen to the structure, the /overall/ damage is minimized.

What’s really cool, though, is that these architectures are inspired by nature

— specifically, by the shells of arthropods.

For example, the mantis shrimp has a giant claw to smash prey at a blinding speed.

To avoid having this claw develop one huge crack,

it’s structured in such a way that microcracks form in a specific helical pattern that distributes

the pressure over a larger area.

That makes the claw less brittle overall.

And now, those helical patterns are being used in construction.

Admittedly, this research is pretty new, so it’s going to take some time to figure out

exactly if and/or how it can be incorporated into future buildings.

But it’s pretty awesome that our solution to a natural disaster could come from nature

itself.

Now, vibrating barriers and nature-inspired materials are cool,

but they might seem pretty standard in the engineering world.

So if you’ve been holding out for a really weird, wonderful example…

we have one of those for you, too.

I’m talking earthquake invisibility cloaks.

Here, you have a series of vplastic rings built into the foundation of your building

of choice.

Each ring has its own specific stiffness and elasticity to absorb a certain frequency of

wave.

When an earthquake hits, the rings deform and deflect some of the ‘quake’s energy

along themselves,

moving that energy around the building so that the people inside never feel a thing.

Basically, the building becomes “invisible” to earthquakes.

I mean, this isn’t great news for the next building over if it doesn’t have its own

protection,

but I guess this technology lives in a world where it does.

The more rings you have, the more frequencies you can cover.

And you don’t necessarily need a hundred of them, either —

you just need enough to take care of the most abundant frequencies, and the ones the building

is most sensitive to.

Also, as a huge bonus, these rings don’t have to be massive.

For a ten meter-wide building, each ring would only have to be about ten centimeters thick.

This technology started getting attention around two thousand nine, though, so there

are obviously a few things to work out before it starts popping up in the real world.

But like the other developments we’ve talked about, it is really promising.

At the end of the day, the Earth isn’t going to stop throwing earthquakes at us.

But these kinds of innovations mean that, maybe one day, we won’t have to worry too

much about the next big one.

Earthquakes aren’t the only challenge engineers have to tackle, though.

Their work involves everything from traffic to suspension bridges —

and if you want to learn more about those fields, you can check out the Infrastructure

chapter in the Physics of the Everyday course from Brilliant.

It even has a whole section about skyscrapers.

One thing I learned was that many skyscrapers have a center of mass that’s below the surface.

That helps stop them from falling over, and it’s cool to think about.

This course has plenty of other facts, diagrams, and interactive quizzes, too,

so whether you want to learn about skyscrapers or airplanes, there’s probably something

there for you.

Also, if you download Brilliant’s iOS app, you can get their courses offline!

To learn more, you can head over to Brilliant.org/SciShow.

And if you want to get yourself an annual Premium subscription, the first 200 people

to sign up at that link will get 20% off!

[ outro ]