Study of the Applicability of Modal Pushover Analysis on Irregular Continuous Bridges

摘要

The influence of higher modes and their consideration in the pushover analysis of three irregular continuous bridges is discussed. Modal pushover analysis (MPA) is addressed and compared with inelastic time-history analysis (ITHA). In the operation process of MPA, each important mode is used to determine the distribution of forces for the pushover analysis separately, and the displacements of different parts of bridge are monitored to construct pushover curves for each important mode. When the analyses for all important modes of one bridge are completed, the results are combined and compared with the results of ITHA. The investigation shows, for each important mode, adopting different displacement-monitored points obtains different pushover curves. If reasonable pushover curves are selected as capacity spectra, MPA can give the results comparable with ITHA, or else MPA does not work well. Finally, how to choose reasonable displacement-monitored point to construct capacity spectrum of MPA is identified.