Seismic risk reduction: the role of seismic microzonation

In 2007 the Regione Emilia - Romagna issued microzonation regulations that require : 1-for every municipality of the region a geological survey with the goal of identifying the sites susceptible of seismic site effects (level 1); 2- for municipalities belonging to the seismic categories 2 and 3 a microzonation map (level 2) and finally 3- a detailed investigation for sites of relevant economic importance (level 3). Our paper is dealing with the amplification tables contained in the regulations (and actually built by the authors) . These tables allow to compute amplification factors in term of horizontal PGA and Housner spectral intensity and are dependent on the geological characteristics of the area. We show that the results expected by the tables were confirmed by the experiments. The May 2012 Emilia-Romagna earthquake has proven the validity of these tables and emphasized the importance of soil conditions, that is microzonation, to evaluate, and then reduce the seismic risk.