Probabilistic seismic damage characteristics of simply supported steel box girder bridge across fault

Taking a simply supported steel box girder bridge across strike slip fault as the study object, simultaneously considering effects of uncertainty of ground motion and structural parameters, the incremental dynamic analysis (IDA) of the whole bridge structure under non-uniform excitation was performed, and probabilistic seismic damage characteristics of bridge piers across fault were deeply discussed. The results showed that effects of structural parametric uncertainty increase with increase in ground motion intensity; for pier adjacent to fault, when slip thrust strength of fault is 78.0 cm, the exceeding probability of complete failure rises from 7.53% of the mean model to 13.01% of the random model, so the vulnerability of the structure may be underestimated if not considering effects of structural parametric uncertainty under strong earthquake; when slip thrust strength of fault is 52.0 cm, exceedance probabilities of pier not adjacent to fault are 97.54%, 88.51%, 2.42% and 0.06%, respectively under four damage states, while those of pier adjacent to fault are 99.24%, 99.15%, 6.50% and 0.28%, respectively, so more attention should be paid to aseismic design of bridge piers adjacent to fault and targeted aseismic design should be performed. © 2021, Editorial Office of Journal of Vibration and Shock. All right reserved.