Shake it Up!
Create an Earthquake Proof Building
Earthquakes can really rock our world inside and outside of our homes. Structural Engineers have been developing building techniques to improve a structures likelihood of survival in the case of an earthquake. Today your challenge is to build a structure that can withstand the shaking of an earthquake.
Make a Shake Table
But first you must create your shake table base that you will put your structure on to test it. You will need two equally sized books or boards, 4 equally sized balls (rubber balls or golf balls work well) and two rubber bands. (I have four pictured but you really only need two.)
Assemble by sandwiching the balls between the cardboard and securing with rubber bands. To simulate the earthquake, shake the base back and forth. The balls allow flexibility of movement in all directions!
We know that simple house construction does not hold up under the shaking of an earthquake. So, you must brainstorm ways to make it stronger don’t forget to draw your design for a full visualization before you build.
Build a Structure
You can use anything you have to build the structure. Some suggestions are toothpicks and marshmallows, straws and paperclips or coffee stirrers and clay. Cardboard and paper might work, Lego or Jenga blocks too!
Once your structure is complete, test it out! Place it on your shake table and shake! If it fails, that’s OK! Identify its faults. Brainstorm ways to make it stronger. Redesign and test again!
Extra Challenge
Once you have a design that works see how tall you can make the structure. Can you double its height without ill effects on the stability?
Dig Deeper
Here is a cool add on: download the Science Journal by Google app onto a phone. This is a free app that has some really cool features. My favorite for this activity is the accelerometer. It can measure the acceleration of the phone moving back and forth, up and down or forwards and backwards in meters per second. Try downloading the app.
Open the accelerometer. Take a few minutes to play around with it. Change it from measuring the x axis to the y axis and finally the z axis. Do you notice that there is continuous acceleration being measured on the z axis? This is actually the acceleration we experience on earth due to the pull of gravity!
Now get ready to use the accelerometer to measure your simulated seismic activity. Make sure it is recording on the correct axis. Then put it on your shake table and shake! Give your table an initial shake and then let go. What do you notice about the movement over time? When is it strongest?
Check out this video for a great way to use this app and your shake table!
Here is a video of a shake table at University of California used for research and testing of a variety of structures.
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