A procedure for estimating the risk and resilience of bridge networks under both seismic and tsunami hazards

To develop disaster mitigation measures in regions affected by both ground motions and tsunamis, it is important to consider the effects of both seismic and tsunami hazards and assess the social impacts associated with economic losses and reduced network functionality. In this paper, a procedure is presented for estimating the risk and resilience of bridge networks under both seismic and tsunami hazards. Using the proposed framework, it is possible to estimate risk as the economic loss and resilience as the functionality and recovery time of a network after an earthquake. In an illustrative example, the road networks in two Japanese cities expected to be affected by the anticipated Nankai Trough earthquake, which would cause strong ground motions and a subsequent tsunami, are analyzed. Using risk and resilience as performance indicators for social impacts, the effectiveness of retrofitting a road structure can be quantified. Finally, the retrofitting prioritization for various structures can be determined.