Time-Dependent Damage Evolution of Reinforced Concrete Bridge Piers: Implications for Multihazard Analysis

Explicit multihazard analysis of structures, especially bridges, has attracted significant attention from researchers and practitioners. Depending on the number of hazards considered and the length of the time interval, such analysis can be time-consuming and cumbersome for practical purposes. Therefore it would be beneficial to determine under what conditions such analysis is necessary. This paper explored the damage scenarios and performance criteria under which typical overpass bridges in the US require an explicit multihazard analysis. The paper concentrated on three common hazards (in addition to gravity loads): seismic, scour, and corrosion. Throughout the analysis, seismic hazard was assumed to be dominant. To explore this question, the paper used a probabilistic methodology to model time-dependent damage processes in RC. The dominant uncertainties in the modeling process are those associated with earthquake occurrence and intensity, corrosion initiation time and rate, and stream flow intensity. To quantify structural damage, a Park-Ang damage index is used. The damage index evolves with the age of the simulated structure and the combined effect of multiple hazards. It was found after examining several realistic bridge designs that the combined effect of multiple hazards throughout the life of the structure becomes important when evaluating low-probability damage events (such as collapse).