Development of a seismic design methodology for precast concrete floor diaphragms

A multi-university research project is being performed to develop a comprehensive seismic design methodology for precast concrete floor diaphragms in the United States. The effort, funded jointly by the Prestressed/Precast Concrete Institute, the National Science Foundation, and the Charles Pankow Foundation, involves an integrated analytical/experimental research approach and strong industry oversight. Full-scale experiments of isolated diaphragm details were used to build analytical models of diaphragms for use in non-linear static ("pushover") analyses and nonlinear transient dynamic analyses. New details have been developed and are being tested through hybrid (adaptive) experiments of precast panels integrated with computer dynamic analyses. Diaphragm force amplification factors, capacity design rules, and diaphragm detail classifications are being developed for the emerging seismic design methodology. A half-scale shake table test of a three-story diaphragm sensitive structure (one floor of untopped double tee, topped double tee and topped hollow core) will be performed to demonstrate the design methodology.