Life-Cycle Resilience Measurement of Bridge Pile Foundation under Scour Hazard Based on Probabilistic Hydrological Information

Due to the scarcity of existing research on scour resilience, it is challenging to quantify the long-term resilience of bridge pile foundations under scour conditions. In this paper, a quantitative framework to measure the scour resilience over bridge life cycles based on probabilistic hydrological information is presented. First, a bridge pile foundation functionality profile under scour hazards was developed, incorporating the characteristics of scour hazards and intervention scenarios. The fractionally differenced autoregressive integrated moving average model was then applied to daily discharge data to generate life-cycle hydrographs. Second, a three-dimensional bridge pile foundation finite-element model (FEM) considering scour development was established, using the bridge life-cycle scour history as input and the bridge damage indicators as output. The time-varying bridge damage indicators generated from FEM analysis were used as input for the pile foundation functionality profile to compute the life-cycle scour resilience. Finally, the framework was applied to a hypothetical bridge on the Red River near Fargo, ND. The results provide the distribution of scour repair measure execution times and corresponding scour depths over bridge life cycles, highlighting that the maximum resilience enhancement is achieved when repairs are conducted as the bridge pile foundation sustains a moderate damage level.