The March 2011 Fukushima Daiichi NPP disaster was primarily caused by initiation of tsunami of the Great East Japan Earthquake which resulted in the failure of flood defence structure (sea wall), leading to the shutdown of the NPP. As a result of this catastrophic incident, focus has shifted to reanalyze potential flooding and seismic effects using state-of-the-art knowledge of these extreme events. This study presents a methodology for developing combined fragility surfaces of flood defence structures for earthquake and flooding hazards. As a case study, the dynamic analysis is carried out on a 2D non-linear elastic plain strain finite element model of Pine Flat Dam considering both the fluid-structure (FSI) and soil-structure (SSI) interactions
