33.16.2. Demand-Capacity Ratios

Try these first

1. 1.

   What does a Demand-Capacity Ratio less than one indicate?

   Hint

   Consider safety under expected conditions.

2. 2.

   Define Pushover Analysis.

   Hint

   It tests the structure to the brink of failure.

3. 3.

   What is the Demand-Capacity Ratio?

   • A measure of total mass
   • Comparison of demand to capacity
   • A structural analysis technique

   Hint

   Focus on how DCR relates to demands and capacities.

4. 4.

   A DCR above one indicates:

   • True
   • False

   Hint

   Consider what a safe capacity means.

5. 5.

   You’re tasked to evaluate a new high-rise building planned for an earthquake-prone area. The seismic design spectrum indicates a demand that exceeds the initial capacity derived from pushover analysis. Discuss potential design changes.

   Hint

   Focus on safer building practices.

6. 6.

   Considering a bridge with a Demand-Capacity Ratio of 1.2. Explain the implications for safety and potential mitigation strategies.

   Hint

   Think about the choices engineers have for safety.