Abstract：Elastic-plastic time-history analysis is a strict method to calculate the seismic response of bridge structures. However, it is not convenient to engineers because it is quite complicated and has a large amount of calculations. To solve this problem, a mode-based pushover analysis method (MPA method) is developed. MPA method is applied to the antiseismic performance analysis of a continuous rigid frame bridge with high piers. According to the construction design codes in China, the sum of participating masses of vibration modes should exceed 90%. Based on the modal participation mass ratios, some high order vibration modes are taken into account in the analysis while those vibration modes with the modal participation mass ratio less than 1% are neglected. In this way, the large number of computations can be avoided while the effect of high order modes can be considered. Thus, MMPS method (modified mode-based pushover analysis method) has been developed. A comparison between the MMPA method and the elastic-plastic time-history method has been made. The result shows that the proposed method (MMPA method) has a satisfactory accuracy. It is an easy-use method for bridge engineers.
2010, Vol. 29 
