Earthquake Resistant Buildings

[Image of a toothpick and marshmallow building: a house made out of toothpicks and marshmallows.] Objective: 1. Use the Engineering Design Process to build a model structure that can resist an earthquake. 2. Discover factors that make a house resistant to earthquakes by observing other student’s designs. Prerequisite Knowledge:

NSTA Science Process Skills:  Observe:

 Measure:

 Infer:

 Sort:

 Predict:

 Communicate: Accessibility: [Specific changes to procedure in blue and in parentheses] What You Need:  Plate, aluminum pie, 6” diameter – 1 per 2  Round toothpicks – 1 box per 8  Flat toothpicks - 1 box per 8  Mini marshmallows, fresh – 1 bag per 10  Cup, plastic tumbler, 9 fl. oz. – 1 per 2 + 2  Jell-O, flavored - 1 box per 4  Gelatin, unflavored – 1 packet per 4 Preparation:  Prebuild a small house out of the marshmallows and toothpicks as pictured at the start of the lesson.  Prepare double strength Jell-O before this activity. Use 1 packet Jell-O and add 1 packet of the unflavored gelatin. Make the rest of the recipe as directed. Pour the resulting liquid into pie plates about 1 inch deep. Refrigerate 12 hours.  Premeasure the marshmallows into cups for student use. Make 2 cups extra. What You Do: 1. Ask, “Does anybody know what happens during an earthquake?” 2. Explain, “The land jiggles either side to side or up and down, usually both. It can split and sink or come together and rise. What happens to a specific piece of land is hard to predict. We can leave it to say that it jiggles. [The solid ground is under enough pressure that it behaves as a liquid.] 3. Tell, “We are going to build houses on the Jell-O and see whether they can stay up in light, medium, and heavy intensity earthquakes. We will use marshmallows and toothpicks to build the houses.” Show the simple example house. 4. Tell, “First we need to practice our low, medium, and high jiggling. A low jiggle should be a single, one fingered tap on the bottom of the plate. A medium jiggle can be a shake left, then right. A high jiggling can be a shake of both up/down and left/right direction. 5. Show students how to connect the marshmallows and toothpicks by stabbing the toothpick into the marshmallows. The buildings can have their foundation toothpicks pushed into the Jell-O. 6. Pass out paper and pencils. Direct students to briefly draw what their building will look like. The sketches don’t need to be perfect; they do need to include how big the building will be and any special features. 7. Direct students to come to you at the Jell-O table and show you their plans. If the plans contain size and special feature information, give students their Jell-O and direct them to the cups of marshmallows and toothpicks. 8. After students have constructed their buildings, as a group conduct the low intensity jiggle. Most buildings should remain standing with minor damage. Stop and assess for damage [i.e. loose toothpicks, foundation damage, roof shifting]. 9. Perform the medium shake as a group [once left and once right] and assess for damage. 10. Perform the high shake [left/right and up/down] as a group and assess for damage. 11. Ask each group: a. Tell us your idea for the house.

b. Were there any special features to make it strong against earthquakes?

c. How did it do in low, medium, and high shake earthquakes? 12. Ask, “What was in common with the structures that were strong against earthquakes?” Record these results on the board. 13. Tell, “Now we’re going to build again differently to build a better earthquake resistant house. This is what engineers do sometimes. They build a model and try it out, then build a better one. Please reuse as many of your building materials as you can.” 14. Direct students to draw a new plan on the same piece of paper as the old plan. When they are done with the plan they can start. If students are having difficulties making a new plan, ask them what didn’t work about their old plan and what they could try to fix it, or repeat the results from the board. 15. As students finish, they can do a low test at their table to look for weaknesses. 16. Perform the low, medium, and high shake tests as a group. Ask each group: a. What did you change? b. Did it improve how strong your building was? c. What would you do if you had one more chance? 17. Students may eat their results. Otherwise put uneaten marshmallows, toothpicks, and Jell-O in the trash. The pie pans are reusable after a soak. 18. After students have cleaned, while they are eating ask: a. What happened to the tall houses? b. What happened to the short houses? c. What happened to the wide houses? d. What kinds of shapes or special features made a building more stable? e. What kinds of shapes or special features made a building less stable? f. Record the answers on the board. Student questions: 1. What happened to the tall houses? 2. What happened to the short houses? 3. What happened to the wide houses? 4. What kinds of shapes or special features made a building more stable? 5. What kinds of shapes or special features made a building less stable? Differentiations: 1. Add a reading component. After students have tried these experiments, present them with an age appropriate article on earthquake resistant design. After reflecting on the reading give the students one more design cycle. 2. Change the Jell-O to sand. This can potentially increase the mess, but can illustrate the same point. 3. Make a shake table according to this design. The top portion of this table can be pulled back to different distances to simulate different earthquake strengths. NGSS Alignment: K-2-ETS1-1; K-2-ETS1-2; K-2-ETS1-3; 3-PS2-1; 3-ESS3-1; 4-ESS3-2; 3-5- ETS1-1; 3-5-ETS1-2; 3-5-ETS1-3 CCSS Alignment: W.2.8; MP.5; W.3.7; W.3.8; W.5.7; W.5.8