Multihazard Earthquake and Tsunami Effects on Soil–Foundation–Bridge Systems

Large earthquakes and tsunamis can damage or lead to the collapse of lifeline bridges, resulting in human and socioeconomic losses as well as prolonged recovery times. Although many simulation models are available for the individual effects of earthquake and tsunami hazards on bridges, there are limited modeling approaches for predicting damage from sequential earthquake and tsunami hazards. A bridge modeling approach, which includes soil–foundation–structure interaction effects, is developed within the finite-element framework OpenSees to quantify sequential earthquake and tsunami-induced damage. Multihazard interaction diagrams that relate earthquake and tsunami intensity measures to bridge system damage show that the residual effects of earthquake loading on the bridge system reduce resistance to subsequent tsunami loading.