PERFORMANCE of MODAL PUSHOVER ANALYSIS on A FIRST MODE DOMINANT MOMENT RESISTING FRAME
Modal Pushover Analysis (MPA) has been recommended by ATC-55 as a tool to estimate seismic demand of structures. It demonstrates significant improvement over the pushover analysis procedure currently used in structural engineering practices due to its ability to predict the higher mode effect. Several studies on medium rise concrete- and steel- buildings designed according to the Indonesian code show tendencies that some structures can not maintain first mode shape due to yielding, and pushover fails to detect some nonlinearity in some structural elements. This study evaluates the applicability and the effectiveness of MPA in predicting structural response of a first mode dominant structure, designed as fully ductile moment resisting frame based on the Indonesian concrete building code. The performance of MPA is compared to the Capacity Spectrum Method and rigorous Nonlinear Time History Analysis (NLTHA). It is shown that MPA can predict well the peak displacement of the structure in the inelastic range, although is not appropriate in calculating total base shear and overturning moment.