Probabilistic assessment of structural performance of bridges under tsunami hazard

An earthquake can cause multiple disasters. For the reliability estimation of coastal structures and infrastructures in Japan, seismic hazard, tsunami hazard and hazard associated with airborne chlorides need to be taken into consideration. Firstly, this paper presents the damage of bridges during the Great East Japan Earthquake and Tsunami on March 11, 2011 based on the Japan Society of Civil Engineers (JSCE) damage investigation. Especially, the damages condition and the possible failure mechanisms of bridges due to tsunami are discussed based on the field survey. Secondly, the tsunami fragility curves are presented. These are used to estimate the structural fragility under the tsunami hazards. Bridge failure probability can be estimated using the tsunami hazard curve and the fragility curve. Finally, an illustrative example quantifying the effect of bridge pier height on the reliability of a bridge under tsunami hazard is presented.