A NEXT GENERATION SCALAR INTENSITY MEASURE FOR ANALYTICAL VULNERABILITY STUDIES

To assess the seismic performance of a structural system within an analytical context, we need, among others, to specify a ground motion Intensity Measure (IM).The wary IM selection is undoubtedly an important step towards the successful implementation of a risk assessment, since insufficient and/or inefficient IMs can induce unwanted bias and variance in the vulnerability estimates.Supplementary issues related to practicality, necessitate the use of IMs for which ground motion prediction relationships exist, such as the elastic response spectral values (i.e.acceleration, velocity and displacement).Several past studies suggested as an improvement the use of IMs defined as the geometric mean of spectral acceleration values computed over a period range.The latter range may span between periods that are below, at or above the fundamental one.Some of these choices were proven to significantly improve both efficiency and sufficiency of the IM compared to more commonly used counterparts.