Multi-hazard fragility analysis for fluvial dikes in earthquake- and flood-prone areas

The paper presents a methodology for the multi-hazard fragility analysis of fluvial earthen dikes in earthquake- and flood-prone areas due to liquefaction. The methodology has been applied for the area along the Rhine River reach and adjacent floodplains between the gauges at Andernach and Dusseldorf. Along this domain, the urban areas are partly protected by dikes, which may be prone to failure during exceptional floods and/or earthquakes. The fragility of the earthen dikes is analysed in terms of liquefaction potential, characterized by the factor of safety estimated using the procedure of Seed and Idriss (1971). Uncertainties in the geometrical and geotechnical dike parameters are considered in a Monte Carlo simulation (MCS). Failure probability of the earthen structures is presented in the form of a fragility surface as a function of both seismic hazard and hydrologic/hydraulic load.