A Macroseismic Method for the Vulnerability Assessment of Buildings

A seismic risk analysis addressed to earthquake emergency management and protection strategies planning, requires territorial scale evaluation; to this aim a macroseismic method for the vulnerability assessment of built-up area is presented. The method is derived, in a conceptually rigorous way, by the use of Probability and of Fuzzy Set Theory, considering Macroseismic Scale definitions. Damage Probability Matrices are evaluated for the six vulnerability classes considered by the EMS98 scale; vulnerability curves are drawn for these classes and for different building typologies. An analytical equation, interpolating the curves, is introduced as a function of an only one parameter the Vulnerability Index; it correlates the seismic input, in term of Macroseismic Intensity, with the physical damage, summarized by the mean value of the beta distribution. An average Vulnerability Index is associated to each building typology, which may be refined on the basis of a seismic behavior modifier factor, and of a regional factor. A different uncertainty is associated with the vulnerability assessment and the consequent damage evaluation depending on the quantity and quality of data available for the analysis. By the use of statistical correlations, consequences scenarios (collapse, unfit for use buildings, deaths and injuries, homeless) and physical losses can be estimated.