Exploring Risk-targeted Hazard Maps for Europe

In regions where the seismic hazard is calculated using a probabilistic approach, the design of new structures according to modern regulations requires a uniform hazard spectrum for a given return period. The assumption is that the resulting collapse probability is equally uniform for all structures, regardless of their structural properties or location. However, the uncertainty in the collapse capacity and seismic hazard curves at different sites lead to an unequal level of risk across a region. This discrepancy is undesirable given that some inhabitants will be living in dwellings that have a lower margin of safety than others living in structures designed according to the same building code. The estimation of risk-targeted hazard maps allows for the definition of a design ground motion leading to a uniform level of risk. Using hundreds of fragility models developed for European buildings and hazard results from the SHARE project, we calculate risk-targeted hazard maps for a pre-established annual probability of collapse.