Analysis and Design of Inter-Story Isolation Systems with Nonlinear Devices

Seismic isolation systems that mitigate seismic response are generally applied at the base of a building; however, architectural, functional, and cost considerations have motivated the application of isolation systems at inter-story locations. In this article, we systematically examine the effectiveness of inter-story isolation systems as a function of their location, and explore alternative approaches for selecting their properties. Single-story isolation systems are shown to be effective in mitigating force demands above the isolation system but less effective in mitigating forces below the isolation system. Finally, the practical aspects of designing an inter-story isolation system to accommodate light loads are discussed.