34.5.2. Parameters of Spectrum

Try these first

1. 1.

   What does spectral acceleration (Sa/g) measure?

   Hint

   Think about structures and shocks from earthquakes.

2. 2.

   Why is a damping ratio of 5% typically used in designs?

   Hint

   Consider the purpose of having a consistent measure.

3. 3.

   What does the parameter spectral acceleration measure?

   • The speed of the ground
   • The response of structures to ground motion
   • The weight of a structure

   Hint

   Consider how structures react during earthquakes.

4. 4.

   True or False: A higher damping ratio leads to a stronger perceived shaking in buildings.

   • True
   • False

   Hint

   Think about what damping does to energy.

5. 5.

   Consider a building designed with a spectral acceleration factor (Sa/g) of 0.3 on a damping ratio of 5% on soft soil. Calculate the increase in spectral acceleration if the soil were to change to a stiffer type.

   Hint

   Refer to codes that specify how soil type can factor into spectral calculations.

6. 6.

   A building experiences high levels of shaking during a seismic event. How would a higher damping ratio mitigate the effects on the structure compared to a lower one?

   Hint

   Think about the concept of energy dissipation in materials.