Fall of the Leaning Tower
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Student Handout |
Hold It Up
The Tower of Pisa is leaning because it was built on highly unstable ground right above an old river bed. What kind of soil is best to build on? Make your own soil mixture and see how well it supports a brick on end.
Procedure
Your goal is to mix a soil sample that will best support a brick standing on end. Using your materials, work with your group to make a mix you think will leave the least indentation from the brick. Record and illustrate your final soil sample makeup in your journal. Once your mix is done, gently stand the brick upright in the center of your soil sample. Try not to push the brick down into the soil. Let your brick stand overnight. The following day, gently remove the brick and measure the indentation that has been left. Record the depth. Based on the results of your first sample, mix a second sample that you think will better support the brick. Let stand overnight again and measure results.
Think About It
As you design your mix, consider:
each type of soil. Look individually
at each type. Is it fine or coarse? How big are the particles that make it up? Describe and record the characteristics of each type. how the different types of soil might work together. How will the soil types change when you mix them together? Experiment mixing small amounts and see how the soil
characteristics change. Record
your results. your mixing options. Do you want to layer the soils, or mix them all
up? Or do you want a layer on the bottom, a mix, and a layer on the top? Consider which combination might make the strongest foundation for your brick and why.
Questions
Write your answers on a separate sheet of paper.
What did you learn? How were your first and second soil samples different? Explain the reasoning behind any changes you made. If you were to repeat the experiment once more, how would you change your soil mixture? What other variables might affect a soil's effectiveness in holding up a building? Based on what you learned, where might be a good place to build a new high rise in your town?
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