Living in Earthquake Country (6-12)
Overview of the box
Concepts and Standards
Lessons:
1 Earthquake damage
2 Faults are at fault:
Where earthquakes occur
3 Earthquake patterns
4 Seismic waves
5 A whole lot of shakin’
goin’ on!
6 Landslides, liquefaction,
and structural failure
Activities:
1 Shaking and landslides
2 Earthquakes and liquefaction
3 Earthquakes and structural failure
7 Examining all the factors
Online resources
Student Web Page

Extras:
Lessons that use the
Rapid Earthquake Viewer
Teaching Boxes Home
Lesson 6: Landslides, Liquefaction, and Structural Failure

Activity 3

Earthquakes and Structural Failure

Materials / Preparation

  • Reserve the computer lab for this activity.
  • The web activity requires Flash.

Grouping

Students may work individually or as partners.

Teacher tips

This is a web-based activity. Students will determine the best bridge structure to withstand earthquakes of varying magnitudes. Visit the site first and practice the activity – Engineering for Earthquakes - before the students are asked to do so. The activity has audio. You may want to ask the students to either turn the volume down to low, or to turn off the audio – see bottom left of the screen for this option.

Procedures

  1. Start the class by asking students why earthquakes cause structural damage. What kinds of structures are most likely to be damaged? Write on the board all the answers given. Ttaking the answers in consideration direct a discussion so that the students understand that there are various factors that contribute to the failure of a structure during an earthquake: shaking intensity and construction of the structure. Tell students that they are going to be doing a simulation that will test the effectiveness of different types of bridge construction to survive a major earthquake. If you were in charge of building such a project, what are some of the factors that you would have to consider? (safety and cost of construction)
  2. Let the student do the web-based lab entitled Engineering for Earthquakes. This site is accessible from the Earthquake Hazards Student Web Page.
  3. After the students have completed the lab, discuss the lab and direct the discussion such that the students come up with the answer that there are various causes for the structural failure. They should have discovered that the same bridge can withstand a small earthquake but might fall down in a larger earthquake. That’s why it is VERY important for scientists and engineers to be able to predict the largest magnitude earthquake that a fault can produce. For example, scientists have determined that a Magnitude 9 earthquake is virtually impossible for the San Francisco Bay Area, but may happen every few hundred years in the Pacific Northwest. The Bay Bridge would NOT need to withstand a Magnitude 9, but a bridge in Seattle might need to. Why does this matter? It’s expensive to build some types of bridges, so why waste the money building a bridge stronger than you need to? This is one part of a field called “Risk Management.” Students also should have discovered that different bridge designs are more stable than others. Engineers figure out how new design techniques for making structures safer in earthquakes.

Resources used

Engineering for Earthquakes
http://www.teachingboxes.org/catalog.jsp?id=DLESE-000-000-009-350

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