Improving Performance of Buildings in Very High-Seismic Regions, FEMA P-2343

Purpose
This webinar will provide an overview of a new report (FEMA P-2343) that documents a three-year study of the expected seismic collapse performance of modern, code-conforming buildings in very high-seismic regions. The webinar will describe the scope, approach, and analytical methods of the study and will summarize the key findings and recommendations.

Background
Nearly 43 million people and 13 million buildings in the United States are located in very high-seismic regions, such as those relatively close to active faults, but very few prior analytical studies have investigated the collapse potential of buildings subjected to such high ground motions. FEMA P-2343 documents a study of the expected seismic performance of four structural systems common in these regions. The study includes results for building archetypes of these structural systems that represent a range of properties relevant to expected collapse performance.
The analytical results show that probabilities of collapse increase with increasing risk-targeted Maximum Considered Earthquake (MCER) ground motions across all investigated structural systems, despite the archetype design strengths increasing proportionally for stronger shaking as is currently required by national codes and design standards. The trend suggests that seismic design strength in very high-seismic regions may need to be increased in order to achieve ASCE/SEI 7 performance criteria for seismic collapse.