Evaluation of Modal and FEMA Pushover Analysis Procedures Using Recorded Motions of Two Steel Buildings

Abstract

The objective of this investigation is to evaluate the FEMA-356 Nonlinear Static Procedure (NSP) and a recently developed Modal Pushover Analysis (MPA) procedure using recorded motions of two steel buildings that were damaged during the 1994 Northridge earthquake. It is found that the FEMA-356 NSP typically underestimates the drifts in upper stories. Among the four FEMA-356 distributions considered, the “Uniform” distribution led to the most excessive underestimation indicating that this distribution may be unnecessary. The MPA procedure, in general, provides much-improved estimates of the response compared to the FEMA-356 NSP.