Analytical approaches for the design of base-isolated structures

The seismic response and resistance mechanisms of base-isolated structures are inherently different from those of fixed-base structures. Recognition of this difference and the specific features of seismic isolation response necessitates special analysis techniques that may not be the same as the conventional analysis methods used for fixed-base structures. At the same time, a set Of design and analysis requirements have been developed and incorporated into building codes. The current code requirements, for the most part, are extensions of those specified for fixed-base structures. Thus, same of the special features of seismic isolation response are not currently addressed in building codes. In this paper, the aspects of the seismic isolation response that are specific to base-isolated buildings are discussed, and analysis techniques to quantify their effects are presented.