Dynamic Response of Multi-Storey Structures Seismically Isolated Using Kinematic Bearings

Abstract

A storey comprised of free-standing columns that may uplift under ground motion excitations can be regarded as a seismic isolation technique. These columns are referred to the literature as "kinematic bearings" and have been used in Russia and the wider region of the former Soviet Union over the past 40 years. Despite the extensive use of kinematic bearings, there are only limited studies based on the results obtained by the analytical solution of the dynamic response of such structural systems. From this point of view, in the present study the dynamic response of multi-storey structures placed on the top of a kinematic storey is examined. For this purpose an analytical model that describes the dynamic response of such structures is introduced. As long as the curved configuration of the ends of the kinematic bearings can affect the post-uplift stiffness of the kinematic storey, modal analysis is performed and the dynamic properties after the uplift are demonstrated. Subsequently, dynamic time history analyses are performed and the effect of post uplift stiffness of the kinematic storey on the displacement response of the base is investigated. Finally, the seismic demands of the superstructure, as well as their distribution throughout the storeys are examined.