Failure probability of a liquid storage tank with three-dimensional base-isolation under earthquake action

Abstract

Liquid storage tanks are widely used in the petrochemical industry, but the fixed-base liquid storage tanks have a high probability of earthquake damage, therefore, the research on isolation and damping control of liquid storage tank has attracted wide attention. Based on the dual control requirements of the seismic response of the liquid storage tank itself and the liquid sloshing wave height, a new type three-dimensional isolation bearing suitable for the liquid storage tank has been obtained. Taking into account the material nonlinearity, the liquid-solid coupling, and the liquid sloshing characteristics, a numerical calculation model of the new type three-dimensional isolated liquid storage tanks is established by ADINA. The seismic vulnerability of the fixed-base and the new type three-dimensional isolated liquid storage tanks are investigated, the failure probability of liquid storage tank under different limit states is discussed, and the annual average failure probability and design life failure probability of the liquid storage tank are finally analyzed. The results show that, the probability of fully damaged wave height and axial stress of fixed-base liquid storage tank is 72.0% and 49.6% respectively, under the 9 degree rare earthquake. Compared to the fixed-base liquid storage tank, the failure probability of the axial compressive stress, hoop stress, and liquid sloshing wave height of the isolated liquid storage tank is significantly reduced, but the displacement of the isolation layer becomes the most easily damaged dynamic response. Besides, the new type three-dimensional isolation can significantly reduce the annual average failure probability and the design life failure probability of the liquid storage tank.