Response Reductions in Base-Isolated Liquid Storage Tank Under Far and Near Field Seismic Excitations

Abstract

AbstractThe seismic control of a base-isolated liquid storage tank (LST) is investigated in detail for several parametric variations. Response reductions are evaluated for shear forces, overturning moments, top board displacements, and hydrodynamic pressure. The amplification in sloshing height is also analyzed for maximum control. The parameters for ground motion differ in the form, PGA, ratio between the two components of ground motions, angle of incidence, and effective isolator time period. For the study, a square-concrete LST of dimension \(6\,{\text{m}} \otimes 6\,{\text{m}} \otimes 4.8\,{\text{m}}\) is considered with five isolators. Four isolators are placed at the four corners and one in the center of the LST. The nonlinear time history analysis for bidirectional earthquake ground motion was carried out using ABAQUS. The liquid is modeled by the arbitrary Lagrangian–Eulerian (ALE), whereas the tank is modeled by the solid brick element, and isolators are modeled by the connector elements. The results of the numerical study show that about 75% reduction in the various response quantities of interest can be achieved by five isolators, and the maximum reduction in response quantities almost becomes stationary at an effective time period of the isolator equal to the 2.5 s, and angle of incidence of earthquake does not have a very significant effect on the response quantities of interest.KeywordsLiquid storage tankNear field earthquakesSloshingABAQUSALE