Shaking table test of three-dimensional base-isolated liquid storage tanks in power plants

As one of the core components in power plants, liquid storage tanks are responsible for storing critical materials such as coolant and fuel. Their seismic reliability is therefore essential to the safe operation of the entire power plant system. To address this concern, a novel three-dimensional isolation bearing was developed in this study, and a series of shaking table tests were conducted. The experiments focused on investigating the dynamic characteristics and seismic response of the tank, and the performance of the proposed isolation bearing. The results indicate that the storage tank exhibits excellent seismic resistance, with no structural damage observed during the tests. Additionally, the vertical fundamental frequency of the tank was found to be significantly higher than the predominant frequency range of typical ground motions, suggesting a relatively low demand for vertical isolation. Furthermore, the proposed three-dimensional isolation bearing demonstrated effective horizontal isolation performance. However, the tests also revealed that under triaxial excitation, the isolation system exhibited noticeable rocking behavior, which may cause internal liquid leakage and, more critically, pose a risk of tank overturning. Finally, this study used numerical simulations to verify that the incorporation of viscous dampers in the 3D isolation bearings can significantly enhance their vertical isolation performance, and corresponding recommendations are proposed regarding the arrangement spacing of the isolation bearings.