Mitigating seismic response in liquid storage tanks through meta-foundations

In civil engineering meta-material-inspired periodic foundations are used to improve structure longevity and stability. This paper presents a study focusing on the seismic response of a liquid storage tank supported by a meta-foundation, featuring periodically repeated layers of concrete and rubber. The research starts with a parametric study to determine practical height values for layers in the meta-foundation. This study enhanced meta-foundations by substituting uniform layers with rubber blocks, leading to a better ability to widen the Width of First Attenuation Zone (WFAZ) and reduce the Lower Bound of the First Attenuation Zone (LBFAZ) for wave mitigation. In this unique seismic isolation foundation design, the initial attenuation range spans 1.02–14.99 Hz, preventing seismic waves of these frequencies from propagating within the foundation. To thoroughly assess the efficiency and performance of the meta-foundations, the finite element method is used with a Coupled Acoustic–Structure (CAS) approach. Three meta-foundation configurations were examined for their performance in supporting a liquid storage tank, and their results were compared with those of conventional concrete slab foundations under actual earthquake conditions. Comparisons revealed decreased impulsive hydrodynamic pressure, sloshing displacement, and base shear, alongside increased relative tank displacement, with a reduction in tank wall stress.