Experimental investigation of a collaborative flexible-base rolling-isolation system for mitigating soil-structure interaction in vertical storage tanks

Traditional foundation isolation techniques improve the seismic performance of vertical storage tanks but often lead to differential settlement and tank bottom lift-off due to required structural modifications, limiting practical application. This paper proposes a double-layer seismic isolation and damping storage tank that integrates a flexible tank bottom with a rolling isolation device. The innovation lies in utilizing the flexible bottom’s local deformation to mitigate lift-off constraints while employing the rolling device’s long-period horizontal isolation to enhance seismic performance, resolving the inherent conflict between rigid foundation constraints and uplift risks. Seismic responses were investigated through shake table tests incorporating soil-tank-liquid dynamic interaction. Results show that the novel tank significantly reduces wall acceleration and deformation, with maximum damping ratios of 80.2% and 89.25%, respectively, though its control of liquid sloshing wave height is limited. Considering soil-structure interaction, the novel tank exhibits substantially lower seismic responses than conventional isolated tanks without such consideration, demonstrating that the collaborative mechanism effectively decouples the superstructure from site soil dynamics, thereby attenuating the adverse effects of ground motion.