Building a Shake Table Do you want to see how the structures you've designed designed will stand up in an earthquake? One way you can do this is by testing them on a shake table or seismic simulator. simulator.
What is a shake table? To study the effects of earthquakes on structures, researchers at the ultidisciplinary !enter for "arthquake "ngineering #esearch #esearch $!""#% mechanically recreate these natural disasters in their laboratory at the &tate niversity of (ew )ork at *uffalo $*% using an earthquake simulator or shake table.
The shake table is a + feet by + feet square platform made of concrete poured around a steel frame, with a ferrocement e-terior $concrete and wire reinforcement%. t has five degrees of freedom, meaning it can move in five separate directions. The table can move hori/ontally and vertically, vertically, as well as roll back and forth, rock from side to side, and twist on a central a-is. 0 computer system is used to control the motion of the table. The system enables researchers to input any one of more than one thousand earthquake records records into the table and simulate vibrations of actual past earthquakes. n addition, researchers can create their own earthquake as well as test anything beyond e-isting recordings on the #ichter scale.
What should I consider when I design my own shake table? •
!ost of table and materials for models
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1easibility of construction
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0bility of the table to take the weight of the different materials
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Directions of motion 22 the more the better
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&cale 22 the larger the better
What can you test on a shake table? •
*uilding models
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*ridge models
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&oil, sand, and water combinations
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!omponents of buildings and bridges, such as beam and column connections, walls, and foundations
What are some things you can learn? •
(ot all structures perform alike during the same ground motion
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&i/e, shape, and materials used in structures make a difference
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&tructures have a natural period of vibration
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&tructures have a certain level of fle-ibility
*uildings' contents are affected by3 •
the ground shaking
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the building's earthquake resistance
Two different styles of shake tables that you can build Shaker Board
Materials: •
marbles
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coffee can lid
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piece of wood $or wooden platform%
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bo- lid $about +45 depth%
Procedure: •
&taple plastic lid to wooden block
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6ut marbles under the lid. "-periment with varying amounts and si/es.
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6lace marbles, plastic lid, block of wood in card board bo- lid to contain amount of movement.
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6lace structures on the wooden block and simulate an earthquake. •
1irst do back and forth motion to imitate 6 waves $more accurate if very rapid%
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(e-t do vertical or side to side motions to imitate & waves $more accurate if very rapid%
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&urface waves, with a gentle rolling motion, will arrive later
Shake Table
Materials: •
bo- insert
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bo- with top flaps cut off
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kite string or twine
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marker
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paper clips $7 large si/e, 8 butterfly%
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popsicle sticks $9%
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rubber bands $7 heavy si/e%
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ruler
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scissor
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washer
Procedure: The shake table consists of a bo- $with flaps cut off% and an inner bo- insert that will be the floor of the shake table. The movement of the shake table is done by pulling on the kite string from each end and underneath the bo-. The rubberbands also help simulate movement and shaking. Final Considerations: :hichever shake table you build, observe the motions of each of your structures on it. 0ttach all of your structures to a single base so motions can be better observed. :hich part of the structure moves the most? The least? ;ow could you improve your structure?
Additional Resources: •
Connected²Teaching offers a unique real2life scenario in earthquake engineering design, affording students the opportunity to increase their understanding while motivating them to learn more and to e-plore the fascinating world of &T".
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*lack, *. $+<<=, arch <%. Quake-proof building. &cholastic (ews, "-plorer "dition 7, ;ands2on &cience &upplement
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Bracing for the big one. $+<<=, October%. &uperscience *lue, pp.+92+>.
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!hayet, *. $+<<=, arch <%. Bending without breaking. &cholastic (ews, !iti/en "dition 9, ;ands2on &cience &upplement.
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Northwest Earthquake Workshop for Teachers $(.".:.T% $+<<=%. 6acific &cience !enter.
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&alvadori, . $+<<=%. The art of construction: Proects and principles for beginning engineers and architects. !hicago3 !hicago #eview 6ress.
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&antilli, !. $+<<%. !ids for architecture. !onstruction &pecifier, >8<+.
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&hake *oard developed by Dr. @oyce #. *lueford, Plate Tectonic "#cle of the $ntegrating %cience& 'ath& and Technolog#.
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&hake Table developed by :alter Autschke from the (orthwest "arthquake :orkshop for teachers.
