Influence of the multi-pulse near-fault earthquake motion on the seismic risk evaluation for reinforced concrete bridge

Abstract

The multi-pulse near-fault earthquake motion imposes unique influence on the seismic risk for bridge structure. Regarding the different character of multiple pulse-like waveforms embedded in the near-fault seismic signal, the mother wavelet in wavelet analysis should be adaptively selected for best representation of the embedded multi-pulse seismic signal. A novel adaptive mother wavelet selection procedure is proposed to identify the optimum mother wavelet for each dominant pulse. The seismic risk for the example bridge system is analyzed by incremental dynamic analysis. The result indicates that the identified most unfavorable seismic signal dominates the bridge system fragility compared with the recorded horizontal signals. The top and bottom boundary of the expected annual loss ratio of the unfavorable seismic signal is 4.67% and 6.22% larger than the average value of recorded horizontal signals, respectively. It is necessary to consider the influence of the identified unfavorable seismic signal on the seismic risk for the bridge system compared with the recorded horizontal seismic signals.