IMPROVED ADAPTIVE SPECTRA-BASED PUSHOVER ANALYSIS FOR ESTIMATING SEISMIC PERFORMANCE FOR BRIDGE STRUCTURES

The traditional pushover analysis procedures are based on the invariant force distributions, but none of the invariant force distributions can account for the contributions of higher modes to response. Although the adaptive spectral-based pushover analysis (ASPA) procedure can study the effect of higher modes and considers the dynamic properties of the structures, it is conceptually complicated and computationally demanding for routine application in structural engineering practice. In this paper, an improved adaptive spectra-based pushover analysis (IASPA) procedure which can be employed to analyze practice bridge structures is put forward and proposed. And the seismic performance determined by IASPA is compared with pushover analysis using two force distributions in FEMA-274 and nonlinear RHA procedures. The results indicate that IASPA method provides more superior accuracy in estimating seismic performance on bridge structures.