Seismic regulations
Earthquake-resistant buildings

It was at the beginning of the 20th century, following the earthquakes in San Francisco (April 18, 1906) and Messina (December 28, 1908), that the first earthquake-resistant design rules were proposed. Their aim was simply to impose a certain resistance of structures to horizontal forces, by means of a flat-rate seismic coefficient (of the order of 0.1), possibly modulated according to elevation (higher seismic coefficient for upper floors).

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