30.15. Use of Spectral Acceleration in Performance-Based Design (PBD)

Try these first

1. 1.

   What does Sa stand for in the context of seismic design?

   Hint

   Think about what the term 'spectral' refers to in engineering.

2. 2.

   How is performance point determined?

   Hint

   What two graphs are critically involved in PBD?

3. 3.

   What is the main purpose of using spectral acceleration in performance-based design?

   • It measures energy consumption
   • It determines maximum load capacity
   • It assesses structural performance during earthquakes
   • It calculates building costs

   Hint

   Focus on the main goal of performance-based design.

4. 4.

   True or False: The demand spectrum and capacity curve are used to identify the maximum static load a structure can bear.

   • True
   • False

   Hint

   Consider what kind of forces these graphs are reflecting.

5. 5.

   A building's analytical models suggest that its capacity curve intersects with the demand spectrum at a point of 0.5g in spectral acceleration. If this is the expected performance at maximum seismic loads, what steps can an engineer take to improve performance if the actual ground motion is expected to be 0.7g?

   Hint

   Think about how engineers improve structural resilience in anticipation of unexpected forces.

6. 6.

   In a hypothetical scenario, a hospital design incorporates an expanded capacity for a specific performance point at Sa=0.6g. However, it's noted that the capacity wasn't fully evaluated and the demand spectrum shows Sa=0.8g due to site-specific conditions. What should the design team prioritize?

   Hint

   What adjustments can architects and engineers make to ensure safety and compliance under such conditions?