Effect of Pule-Like Ground Motion on Seismic Performance of Concrete-Filled Steel Tubular Arch Bridge

To study the seismic performance of a concrete-filled steel tubular (CFST) arch bridge under pulse-like ground motions, a comprehensive theoretical analysis is made of an actual CFST arch bridge under the action of non-pulse-like and pulse-like ground motions using time history analysis. The actual ground motion records with different pulse periods are first selected for each site condition based on the PEER (pacific earthquake engineering research center) ground motion models using the spectrum match method. Then, a comparative seismic analysis of the CFST arch bridge is conducted with and without consideration of pulse, different pulse periods and the dimensionality of ground motions. Results show that the pulse-like ground motions can significantly affect structural responses; a better bridge site condition results in a larger structural responses, and the amplification factor is between 0.96–19.88. Meanwhile, the difference of pulse periods induces significant variations in structural responses, the change rate is between 10%–133%; the smaller the pulse period is, the more obvious the amplification effect on the structural response is. In addition, the dimensionality of ground motions has smaller effect on structural responses under pulse-like motions than the one under non-pulse-like ground motions, but the effect intensifies as the pulse period decreases. Therefore, it is suggested that not only the pulse effect but also the influence of pulse period, dimensionality of ground motions and site conditions for the location of the bridge should be considered in the seismic design phase of a CFST bridge to avoid erroneous response predictions.