Spectral reduction factors evaluation for seismic assessment of frame buildings

• The best spectral reduction factor to use when applying a nonlinear static procedure is sought.
• Nineteen spectral scaling methods are tested using sixteen frame buildings.
• Each spectral scaling method is appraised by comparing its prediction of five structural response parameters.
• Damping-based scaling methods lead, in general, to a better approximation of ‘true’ dynamic responses.

From a nonlinear static procedure perspective, one of the key issues is the employment of a demand spectrum that takes into account, through an adequate reduction of its ordinates, the hysteretic energy dissipation capacity of the structure being assessed. There are certainly a relatively large number of past parametric studies dedicated to the validation of different approaches to translate such structural energy dissipation capacity into spectral reduction factors, however such studies have focused mainly, if not exclusively, on single-degree-of-freedom (SDOF) systems. It seems, therefore, that verification on full structural systems, such as building frames, is needed in order to verify the adequacy of using existing SDOF-derived relationships in the assessment of multiple-degree-of-freedom (MDOF) systems, in the framework of a proper nonlinear static procedure. Nineteen spectral reduction approaches are considered herein and a generous set of frame buildings, corresponding to different configurations, design type and materials, is used for application. The main goal of this work is hence the definition of the best reduction factor to use when applying a nonlinear static procedure to seismically assess a frame building.