Optimum Seismic Control and Safety Measures in Liquid Storage Tanks by the Amalgamation of Different Passive Control Devices

Abstract

Severe damage and failure of liquid storage tanks (LSTs) due to earthquakes have been observed. Consequently, various strategies for alleviating the seismic safety of LSTs have evolved, of which energy dissipative devices have been mostly favored. This study focuses on the seismic control of LSTs using three passive control devices: baffles, base isolation, and a hybrid combination. The effectiveness of these control devices, especially the last one, under two-component ground motions was not extensively investigated. The responses of LSTs are obtained in Abaqus by nonlinear time history analysis. The control of the response quantities of interest is evaluated under parametric variations, including the location and number of baffles, angle of incidence of the earthquake, and effective period of the isolator. For the numerical study, the behavior of two flexible baffled concrete rectangular LSTs of different aspect ratios is examined mounted on circular base isolators. The results of the numerical investigation show that (1) the effectiveness in the response reduction of the LST depends on the number and arrangement of baffles inside, (2) the response reduction in the LST varies with the period (Tb) of the isolator and reaches a stationary maximum value at a particular value of Tb, and (3) the reduction in response is generally greater for the higher values of the peak ground acceleration.