Nonlinear Finite Element Model for Base-Isolated Tank-Block Systems Implementing Lead Rubber Bearing Isolator Controlling the Nonlinear Dynamic Responses

Abstract Liquid storage tanks are vital infrastructural applications that seek special attention to maintain their efficient functionality. Sometimes, an inappropriate assessment of excessive hydrodynamic force developed by strong seismic motions can induce severe structural damage. Emphasizing this fact, the present research extensively examines the inherent nonlinear sloshing effects of liquid inside a base-isolated container with a submerged block using a lead rubber bearing under different types of earthquakes categorized based on the frequency content. The study emphasizes the impact of different concentric and eccentric configurations of the block on the overall seismic performance of the structure. A mixed Eulerian-Lagrangian method is used to derive the nonlinear finite element model. The developed model is authenticated with the available results. Nonlinear slosh amplitudes are significantly greater than linear amplitudes, highlighting their importance in determining the appropriate freeboard clearance. The impulsive and total pressure components along the tank wall are significantly reduced, while an increase is observed over the block wall as the block height increases in both types of tanks. It is noticed that such components are drastically reduced due to base isolation. Moreover, the impulsive and total base shear is decreased significantly, regardless of the frequency content of the earthquakes. In contrast, the convective base shear exhibits an opposite phenomenon in some of the selected earthquakes. Overall, the contribution of the impulsive component is significant over the convective one in the ground-supported tank, whereas the base-isolated tank shows the reverse tendency.