Loads, Tubes and Bolts: teacher key

How Buildings Stand Up, grade 10 edition, written for 10th grade. A tall building must carry its own weight and fight the wind. See how tubes, cores and dampers work, and how one engineer found a hidden flaw in a New York tower and fixed it.

Read the book. Print this page for the key.

Questions and answers

1. For very tall buildings, which load usually governs the structural design?
   • Live load
   • Sideways wind load (answer)
   • Furniture
2. What does a pile cap do?
   • Spreads the load among a group of piles (answer)
   • Covers the top floor
   • Holds the elevator
3. What was the flaw LeMessurier found?
   • Too many windows
   • Joints bolted instead of welded as designed (answer)
   • A missing damper
4. Why do some towers use sky lobbies?
   • To add extra windows
   • To make elevators slower
   • To stack elevator shafts and save floor space (answer)
5. Which way does Taipei 101's pendulum swing compared with the tower?
   • The opposite way from the tower (answer)
   • The same way as the tower
   • It does not move

Words

• cantilever: fixed-end beam
• caisson: sealed digging box
• decouples: separates
• resonant: naturally swaying