Abstract：In this study, a pushover method was proposed to estimate the elastic-plastic seismic response of concrete-filled steel tube (CFT) arch bridge. Since the seismic response of CFT arch bridge may be significantly affected by the high-order modes, the combination of multiple modals should be taken into account in the pushover method. Firstly, the application procedures of the multi-modal pushover method were elaborated. Then the Chaobai River Bridge was taken as an example, the incremental dynamic analysis (IDA) curves obtained from the multi-modal pushover method and the elastic-plastic time-history analysis of tie-bar model of the bridge were compared. The comparison results show that the maximum response of the structure can be appropriately obtained by the multi-modal pushover method, and the IDA curves obtained by the multi-modal pushover method are close to those obtained by the elastic-plastic time-history analysis, indicating that the method can be applied to engineering practice. For the present example, it was found that the errors for multi-modal combination are 10%~15% smaller than those for single modal.
