The ATC-19 report, Structural Response Modification Factors, was funded by the National Science Foundation (NSF) and the National Center for Earthquake Engineering Research (NCEER). (Published 1995, 70 pages)
This report addresses structural response modification factors (R factors), which are used to reduce the seismic forces associated with elastic response to obtain design forces. The report documents the basis for current R values, how R factors are used for seismic design in other countries, a rational means for decomposing R into key components, a framework (and methods) for evaluating the key components of R, and the research necessary to improve the reliability of engineered construction designed using R factors.
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