Evaluation of the Seismic Behavior of Steel Liquid Storage Tanks under Near and Far Fault Earthquakes

Design, construction and maintenance of liquid storage tanks, which have been extensively used to store liquid in industrial factories, oil refineries and petrochemical sites, are crucial. Vulnerability of liquid storage tanks have been recognized regarding to the experiences of major earthquakes occurred specifically in Japan, United states and Turkey. Therefore, evaluation of seismic responses of steel storage tanks is important. In this research, due to the complexity of ground motion behavior and the effects of different parameters such as frequency content of excitations on damage assessment of liquid storage tanks, more precise seismic analyses under near-fault and far-fault ground motions considering bi-directional horizontal components is carried out. For this purpose, the fixed base steel liquid storage tanks with height to diameter ratio equal to 0.4 is considered. The finite element analysis of the tank-liquid is carried out using ABAQUS software considering fluid-structure interaction based on added-mass method and nonlinear time history analysis. Significant difference between the seismic responses of the tank to uni-directional and bi-directional earthquake is obtained. More interestingly, the effect of frequency content of excitations on the dynamic response of steel liquid storage tanks are discussed.