Seismic responses of base-isolated flexible rectangular fluid containers under horizontal ground motion

Abstract

This paper focuses on analyzing, the results and arguments about the analysis of seismic base-isolated flexible rectangular containers. An equivalent mechanical model of rectangular containers with three lumped masses and six degrees of freedom is used. Lead rubber bearing (LRB) and friction pendulum system (FPS) are two types of seismic isolators, used to isolate the storage tank base. Results show that seismic base isolation can be an efficient way to reduce seismic responses such as base shear, wall deflection and hydrodynamic pressure, but it can adversely affect the free surface sloshing height. The seismic responses of isolated tanks under unidirectional excitation (No interaction) and bidirectional excitation (Interaction) are not considerably different and the results are not very sensitive to the interaction effect of the bearing forces. In any case, the careful choice of the number and the mechanical characteristics of seismic base isolation systems is suggested to achieve good responses.