Comparative Study of the Non-Linear Dynamic Behaviour of Different Seismic Isolation Systems

Abstract

To mitigate the effect of earthquake on the structure, the base isolation technique is the best alternative as a seismic protection system. In this research, a two-degree-of-freedom (2DOF) equivalent model is modelled based on a real eight-level reinforced concrete structure damaged by the Boumerdes earthquake in 2003 is presented. The basic isolation systems considered are four models namely: the first system is a high damping isolator (HDBR), the second system is the friction pendulum isolator (FPS). The third model of the base isolation system is a non-linear model with two horizontal and rotational stiffness springs (SHRS), and finally the last model presents a bilinear spring (SB). The isolators are designed according to the UBC-97 code. Earthquake recordings from Dar-El-Beida of the 2003 Boumerdes earthquake were used as seismic load. A dynamic analysis of the comparative temporal responses of the structure was performed by comparing its dynamic behaviour with that of the fixed base structure. The results obtained reveal a reduction in base shear, stage drift and stage acceleration and an increase in displacement and time period for the structure isolated at the base. The results are presented in tables and graphs.