Seismic Risk Classification (NTC only)

Seismic Risk Classification (specified only in NTC) is an index corresponding to a scale of the seismic hazard, which a building is exposed to, ranging from G (highest seismic risk) to A+ (lowest seismic risk). It is defined as the worst of two partial indices, the expected average annual loss (PAM) and the Life Safety Index (IS-V). For the calculation of the aforementioned indices the PGA ratios for the limit states of Life Safety and Damage Limitation are required, so these limit states should be selected in the Code Requirements/Limit States Module. Selection of the Limit states of Operational Level and Collapse Prevention is not compulsory, however, if these are selected, the procedure will result in a more accurate classification. The lowest calculated values of the PGA ratios for all check type and pushover analyses are considered in the determination of the Seismic Risk Classification. Information about these parameters can be found in the Italian Regulations.