Earthquake-resistant building design.
Students are challenged to research, design, and construct an earthquake-resistant building out of toothpicks. Each group must build a five story tower between 25-30cm tall, using no more than 110 toothpicks and elmers glue. At the end of the lab each design will be tested through an earthquake simulation. The design that withstands the earthquake the longest without breaking or collapsing will win the competition.
Design and build a model building that is resistant to shaking.
1. How do the following variables affect earthquake-resistance in a building?
Height: Buildings that are 20 stories or taller are more likely to collapse than shorter buildings during an earthquake.
Bracing: By adding support to each floor on a building, engineers can prevent damage from earthquake shaking.
Squares vs Triangles: When pressure is applied to the side of an unsupported square the shape becomes more like a parallelogram. When bracing is added to the square to create two triangles, the pressure is dispersed, and the square retains its shape. This is why most structures are built using triangle bracing.
2. What shapes did you use in your design that provided strength to your tower? Mostly triangles because they are the simplest and strongest geometric shape when pressure is applied.
3. How did your group’s design compare to other designs in the class? There were many different places on our designs that collapsed during our earthquake. The main areas include the foundation, a first story failure, and a second story failure. Designs that remained standing through the earthquake used reinforcement in these key areas. For example, using double toothpicks in the foundation and for each story. Or adding horizontal bracing on each floor. The winning designs all used strategic placement of triangles throughout the structure.
Story: a floor, or level, of a building.
Bracing: a support that steadies or strengthens a building’s framework.