Base Isolation for Seismic Retrofitting of a Multiple Building Structure: Evaluation of Equivalent Linearization Method

Table 1

Nominal properties of rubber bearings.

Isolator type	[kN]	[kN]	[kN/mm]	[kN/mm]	[mm]	[mm]	[mm]	[mm]	[mm]	[kg]
SI-S 600/168	1010	5410	0.67	813	600	168	268	318	850	435	18.13	3.45
SI-S 650/180	1260	6260	0.74	854	650	180	277	327	700	507	17.5	3.50
SI-S 800/180	3400	13280	1.12	1506	800	180	281	341	850	835	19.5	4.33

V = maximum vertical seismic load, = maximum vertical design load in Ultimate Limit State (ULS), = effective lateral stiffness, = vertical stiffness, = diameter, = total rubber thickness, = total height (not including anchor plates), = total height (including anchor plates),   = side length of anchor plates, = weight without anchor bolts, = primary shape factor, and = secondary shape factor.