Code vs. PBEE
Potential misunderstandings under the Code, and how PBEE can mitigate them
Buildings status after a major earthquake
Misunderstanding: Buildings designed “to Code” will definitely be undamaged and operational after a major earthquake
Truth: Such buildings can still be significantly damaged after a major earthquake
Limitation: Code only assumes a level of performance of life safety for a typical building at one design earthquake, but does not explicitly design to achieve that performance
Solution: PBEE permits design for different levels of performance and quantifies performance in terms that are accessible to nontechnical professionals
Collapse risk of buildings
Misunderstanding: The Code collapse goals (10% or less chance of collapse after a major event, 1% chance of collapse over the life of the building) will definitely be met
Truth: Actual collapse risk of code-based buildings can be higher than intended
Limitation: No provisions in Code to explicitly verify collapse risk of design
Solution: PBEE requires quantifying the collapse risk
Buildings subjected to low Intensities
Misunderstanding: A code-designed building will definitely not collapse at intensity levels lower than MCER.
Truth: A building designed for major events can still collapse at lower intensities
Limitation: Code does not design for intensities other than the major event
Solution: PBEE includes a range of intensity levels to quantify seismic risk more comprehensively
Other Comparisons
