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