Seismic analysis of a rigid frame continuous cfst truss girder bridge with composite piers

The elastic seismic response characteristics of a rigid frame continuous CFST truss girder bridge with composite piers are studied with Finite Element (FE) method based on the commercial software MIDAS/civil. The FE results show that the fundamental respond mode of the bridge is a longitudinal mode with a frequency of 0.268 Hz, indicating the bridge is flexible enough to resist seismic activation due to its light self-weight The critical regions are in the elastic range under the most unfavorable direction of ground motion, and the resistance requirement in moderate ground motion is satisfied. The longitudinal and lateral displacements on top of the piers are examined, and it is found that the displacement limit for the CFST pier needs further discussion.