Multiple hazard assessment of bridges considering interdependencies

Bridges are in direct interaction with the environment and thus are exposed to various natural hazards such as earthquakes and floods, that may result in severe damage and substantial direct and indirect losses. The multiple hazard events may be subsequent single events (e.g., a flood event followed by an earthquake) or combined multi‐hazard events (e.g., cascading ground failure event after an earthquake). The effect of multiple hazards on bridge fragility is related to the damage level of the bridge components and the associated failure mechanisms that may compromise the roadway network functionality. The scope of this work is to propose an approach for the multiple‐hazard assessment of bridges considering subsequent events and different damage scenarios of critical bridge components, i.e. piers, bearings and abutments. Therefore, the effect of the damage level of critical bridge components and their interdependence on the fragility assessment for subsequent hazard events is investigated. Different damage scenarios and hazard sequences are studied, providing insight into the damage mechanisms and the accumulation of damage. The approach is applied to the multiple hazard assessment of a case study typical riverine bridge in Greece and the results are comparatively discussed.