Table 1: Modal analysis results of mega-sub-isolation system.

ModesPeriod (s)Modal mass participation factorsCumulative mass participation factors

14.71730.78280.7828
22.82450.04500.8278
32.64430.00980.8376
42.59930.00180.8394
51.08680.10670.9461
60.61680.03950.9856
70.42300.01120.9968
80.34170.0030.9998
90.30990.00031.0000