Seismic Control of Base-Isolated Liquid Storage Tanks Subjected to Bi-directional Strong Ground Motions

Damage of liquid storage tanks (LSTs) due to earthquakes has increased the base isolation systems' demand. As base isolation is a proven control system for mitigating the damages in typical load-bearing structures, its implementation in LSTs is undoubtedly of interest. In the current study, the seismic performance of the base-isolated 3D model of concrete LSTs is investigated under two-component earthquakes as not much literature is available on the subject. The ABAQUS software is used for nonlinear analyses of the base-isolated LST in which liquid and isolators are modeled by the arbitrary Lagrangian–Eulerian and connector elements. For the numerical study, two concrete LSTs of the square and rectangular plans are considered with five lead rubber bearing isolators. The change in response quantities of interest is evaluated under parametric variations, including the type of earthquake, peak ground acceleration, the angle of incidence of the earthquake, and the effective period of the isolator. The response quantities of interest considered are shear forces, overturning moments, top board displacements, hydrodynamic pressure, sloshing height, and Von-Mises stress. The results of the numerical investigation show that the efficacy of base-isolated 3D LST should be assessed at least under a two-component earthquake. Further, the study shows that base isolation is highly effective in controlling seismic stresses developed in LST under two-component earthquakes.