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ABSTRACT

This report provides detailed calculations of seismic isolation of a 4-story

hospital building in California. Sliding bearings were used for isolation of the structure, structure maximum displacements have been investigated using both

equivalent lateral force, ELF procedure as well response history analysis, RHA at both MCE and DE hazard levels. The displacement demands obtained for MCE from ELF and RHA for lower bound properties were 32.35 (in) and 32.05 (in) respectively.

For DE, displacement was calculated to be 10.17 (in) and 12.14 (in) for ELF and RHA respectively using the upper bound properties. Bearing maximum axial force using

lower bound properties in MCE event was 943.07 (kip) for ELF and 999.1 (kip) for RHA. The maximum story drift (relative between roof and displaced base of

building) of the isolated structure was 1.08 (in). It looks that there is close agreement between the results of ELF analysis and RHA; this is due to the fact that the building has regular and symmetric geometry where ELF analysis can be applied. Finally, the

safety of the isolator was assessed based on the results obtained from the analyses, and as the conclusion, the selected bearing was found to be safe at MCE event.