SOLUTIONS TO THE SHORT-PERIOD BUILDING PERFORMANCE PARADOX

This paper presents a summary of the lessons learned from studies of the ATC-116 Project to investigate solutions to the short-period building seismic performance paradox – Why do analytical models of code compliant designs predict high probabilities of collapse for short-period buildings contrary to damage observed in actual earthquakes and the judgement of earthquake engineers? The ATC-116 Project, now in its sixth and final year, is being conducted by the Applied Technology Council (ATC) with funding provided by the Federal Emergency Management Agency. The ATC-116 Project studies are: (1) investigating the major causes of the short-period building performance paradox; (2) improving, calibrating, and validating analytical modeling methods with observed performance of buildings in recent earthquakes and full-scale shake table building tests; and (3) developing practical recommendations for improving seismic design practice and requirements in building codes and standards. These studies have rigorously modeled and evaluated the earthquake collapse performance of the most common types of short-period residential and commercial buildings, including wood light-frame construction, typically used for single-family and multi-family dwellings, and reinforced-masonry shear wall and steel braced-frame buildings commonly used for commercial occupancies. The results of the study provide a better understanding of the seismic risk and resiliency of these types of short-period buildings which represent over 90 percent of the building inventory of the United States.