Earthquake response of base-isolated structural system

The analyses for earthquake response of base-isolated structural systems under different foundation conditions are introduced in this paper. A base-isolated structure supported on-homogeneous elastic halfspace is idealized as a lumped-mass system. The characteristics of the halfspace are represented as Voight solid which includes linear springs and viscous dampers. The damping characteristics of lead-rubber laminated isolator are simulated with hysteretic damping model in accordance with experimental results. The horizontal and rocking motions of the foundation in earthquake are considered while the minor coupling effect between the horizontal and rocking motion is neglected. The results show that the effect of different properties of the foundation soil on the earthquake response of base-isolated structures varies with respect to the horizontal stiffness of the isolators.