Multihazard Resilience and Sustainability Evaluation of Coastal RC Bridges under Sequential Earthquake-Tsunami Events

Coastal bridges are particularly prone to damage caused by prior earthquakes, rendering them more vulnerable to subsequent hazards. The potential occurrence of a near-field tsunami can significantly exacerbate this damage, leading to detrimental environmental and economic impacts. Aiming to quantitatively assess these consequences, this study delves into the multihazard resilience and sustainability of a typical coastal Reinforced Concrete (RC) bridge under sequential earthquake-tsunami events. As such, a nonlinear three-dimensional (3D) finite element (FE) framework is established, seamlessly merging the economic input-output life cycle assessment (EIO-LCA) methodology with the principles of performance-based earthquake engineering (PBEE). To minimize the uncertainty in the probabilistic seismic demand model and the subsequent PBEE outcomes, an optimal intensity measure is chosen based on a comprehensive evaluation of efficiency, correlation, and coefficient of variation. Consequently, the multihazard resilience of the coastal RC bridge is assessed according to the repair time, repair cost, and carbon footprint. It is shown that bridges are more vulnerable under sequential earthquake-tsunami events compared to earthquake events alone, leading to notably increased carbon footprints and reduced resilience levels. Overall, the developed framework enhances the assessment of coastal RC bridge performance, providing valuable insights into the consequences for both the environment and socioeconomic aspects resulting from bridge damage during sequential earthquake and tsunami events.