Survey on Major Worldwide Regulations on Seismic Base Isolation of Buildings

Table 3

Return period (T_R) of the design input (years).

Country	Superstructure	Isolation system
Japan	500	500
China	1600 − 2500	1600 − 2500
Russia	1000 − 5000	1000 − 5000
Italy	475 − 950	975 − 1950
The USA [12]	475	2475
The USA [22]	2475	2475
Chile	475	950

Source: authors.