Engineering Earthquake Structures: Day 1

Explain that over the course of the next days, they will be looking into how engineers solve problems that meet our societal needs and wants.  For example, seismic waves during earthquakes can cause great damage and injury.  Engineers take information based in science and math about seismic waves to develop new technologies that can help us solve these problems. 

Ask the students to “talk to the text” as they gain some background about the properties of seismic waves by reading the article, “Earthquakes”.  Remind them of the “Ladder of Discourse”, and that as they interact with the text they should be making “Tweets”, “Huh?’s”, “Found it!’s”, and “Discourse”.  (For more information on how I introduced “The Ladder of Discourse”, see this lesson.)  After reading and interacting with the text, provide students with large chart paper with “The Ladder of Discourse” on it. 

Using the connections and information the students gathered in the articles ask the students to cite the text to answer the following:

• What are some characteristic properties of S waves?
• What are some characteristic properties of P waves?
• Are seismic waves mechanical waves?  What evidence do you have to support this?
• How can P and S waves be used in a positive wave?
• What are some negative consequences of P and S waves?

Provide students with the Seismic Design Principles: Earthquake Structure Challenge Student Sheet.  Explain to them that they are engineers and a client hires them to design them a new building to house their business in California. 

The client is building near a known fault line and thus is concerned about damage by earthquakes.  Your client needs at least a two-story structure to house its workers.  The company has researched and has found that the typical earthquake in their area lasts approximately one minute.  With your engineering team, create a prototype structure that could survive an earthquake lasting this length of time.

Let students know that they will have many constraints for this challenge.  Ask students to recall what a “constraint” is.  Students should respond that constraints are rules or guidelines that must be followed. The constraints are as follows:

• Materials are limited to 50 straws, 20 marshmallows, 20 paper clips, 20 straight pins, and 10 Popsicle sticks.
• You may break/cut the materials; however, these materials are all you get for all of your design tests.  These materials will be reused on each structure.
• The structure must be at least 2 stories tall.
• The structure must be at least 2 stories tall with a height of at least 24 inches tall.
• The structure must not collapse within the first 1 minute of shaking.
• You must use the provided cardboard base for your design.
• Your structure must hold the 200 g mass (bag of sand) somewhere in or on the structure.  The bag of sand can be folded as long as it is 200 g.
• The top of the structure must be enclosed.  No antennae!  

Students connect their structures to the cardboard using straight pins.  Simply sticking a straight pin through the bottom of the cardboard into the marshmallow touching the cardboard will be sufficient to hold the structure in place.

Teacher Note:  You will need a shake table.  Here is the table that I have.  My district purchased this particular tremor table through a grant.  I know that it is expensive!  I encourage you to write a grant yourself!  Or, create your own shake table for less cost!  

In addition, let students know that the client has a few requirements before they will fund the project. 

The client requirements that must be completed prior to funding the construction of your initial and future prototypes include:

1.  A sketch of your prototype.
2.  A verbal explanation of your design choices – You must explain the why you feel your design will be successful.  The client would like you to cite research and seismic design principles in your explanations to prove it is founded in science and engineering.
3. Proof that you considered multiple designs and evaluated them based on criteria (Design Matrix).
4. Evidence of data collected during the design process will be required to fund future prototypes.

In order to fulfill these requirements, break down and explain each portion of the student document.  Direct the students' attention to the Seismic Principles and Research Citations section of the document.  Explain that in order to meet the client's requirements, the design must be based on research and evidence.  This chart can help organize the research. 

Explain to students that scientists and engineers have used data collected from earthquakes to develop, “Seismic Design Principles”.  These principles are known to be helpful in a structure surviving an earthquake.  In order to obtain information about the principles, I put together a website that has some earthquake and seismic design principles resources organized.  In the chart, students must identify a seismic design principle, the title of the source they found the information in, and the practical application of that principle in the design. (In other words, what design choice will you use in your prototype because of this principle?)  Emphasize to students that this section must be completed before they can draw their sketch for their prototype.  In addition, let students know that engineers work in teams with the same goal.  So, if someone in a group finds a great resource or idea, they should share it with their group!

Check in with each group to make sure they are identifying seismic design principles that can aid in their design.  It is important not only to ask them about the seismic design principles they have identified, but how that design principle can be used in their own structure.  The videos below demonstrate some responses students may provide as you ask them these questions.

Let students know that each member of the group must complete research and draw their own unique prototype sketch.  Let the students know that once each member of the group has completed research and drawn a sketch, the group must check in with you for directions on how to complete the “Design Matrix”.

Typically the first day, I do not have students finish their research.  I just want to let them to know to check in with me if they do before moving on.  In the lesson plan for Day 2, I explain the design matrix.