Influence of hydrodynamic pressure on fragility of high-pier continuous rigid frame bridge subjected to ground motion

Abstract

To investigate the seismic fragility of deep-water and high-pier continuous rigid frame bridge subjected to the combined action of hydrodynamic pressure and ground motion, a representative deep-water and high-pier continuous rigid frame bridge is examined to study the influence of hydrodynamic pressure and ground motion on structural fragility. The corresponding damage indicators and conditional exceedance probabilities are defined and quantified. The probabilistic seismic demand model (e.g., pier and bearing) is analyzed using incremental dynamic analysis (IDA) in the nonlinear finite element software OpenSEES. A comparative analysis is conducted to identify the effect of hydrodynamic pressure on the dynamic response of the bridge. Hydrodynamic pressure plays an important role in influencing the conditional failure probability of piers and bearings. Damage probability increases with increasing water depth, particularly for the pier top in the longitudinal direction.