ABSTRACT
A methodology for determining the optimal countermeasure for bridges subjected to ground motion and tsunami is proposed. Seismic and tsunami fragility curves of a bridge pier and bearing are developed considering the effects of seismic damage prior to tsunami action. The structural vulnerabilities against horizontal and vertical forces are investigated separately in this paper. Seismic and tsunami hazard curves are obtained assuming the occurrence of an earthquake. Uncertainties associated with fault movement, hazard intensity and structural vulnerability are considered based on Monte Carlo simulation. The expected recovery time of bridges (i.e. risk) is estimated based on the failure probabilities of bridge piers and bearings, and used to determine the optimal countermeasure for bridges. As an illustrative example, the proposed methodology is applied to bridges which would be affected by the anticipated Nankai Trough earthquake.
