Earthquakes vs. Buildings

Earthquakes vs. Buildings

• Why are earthquakes a threat to buildings?• Earthquakes move the ground violently,

shifting a building’s foundation.– Earthquakes produce several different types of

ground waves, each of which moves the building in different ways

• This can cause the building to collapse

Is this a big deal?

• Many major cities are located right around the Ring of Fire

San Francisco, USA Tokyo, Japan

How can we protect buildings from earthquakes?

• What is the simplest thing that you can think of that would help prevent a building from falling over?– A wide base!

"El Castillo", Chichen Itzu, Mexico

New Materials Lead to New Technologies

• Internal bracing• Base isolation– The earthquake shakes the ground, so if you

isolate the building from the ground, the building won’t shake

– This is like putting the building on really big springs– http://www.youtube.com/watch?v=ZqlXp3czrrM

New Materials Lead to New Technologies

• Taipei 101 Mass Damper

Future Research

• A seismic invisibility cloak– Steer the waves of the earthquake around the

building using special structures buried in the ground

How do engineers know these things work?

• Engineers test their building ideas on a shake table

Model of seven-story building on a shake table, Japan

That’s what we’ll do now!

• In your teams you will design a Lego building• Your goal is to make the building as tall as

possible, but also stable• Your building will be placed on an improvised

shake table, and compared to others• The last building standing wins!

References

• Images and information– Wikipedia.com– Howstuffworks.com