14.10.3. Bandwidth of Earthquake Motions

Try these first

1. 1.

   What is a narrow-band motion?

   Hint

   Think about frequency concentration.

2. 2.

   Define broad-band motion.

   Hint

   Consider how many frequencies are involved.

3. 3.

   What characterizes narrow-band ground motions?

   • High energy spread over many frequencies
   • High energy concentrated in a limited frequency range
   • Energy distributed with no specific pattern

   Hint

   Think about how energy distribution affects risk.

4. 4.

   True or False: Broad-band motions can lead to resonance.

   • True
   • False

   Hint

   Consider the definition of resonance.

5. 5.

   Calculate the risk of resonance for a building with a natural frequency of 2 Hz subjected to a narrow-band motion at the same frequency. What design considerations would you suggest?

   Hint

   Consider what changes could reduce the likelihood of resonance.

6. 6.

   Describe how an earthquake with both narrow-band and broad-band characteristics would affect a high-rise building. What approaches can mitigate these effects?

   Hint

   Think about the strategies you learned for handling varied motions.