INFLUENCE ANALYSIS OF SOIL-STRUCTURE INTERACTION ON THE DYNAMIC RESPONSE OF STORAGE TANKS

A near-field finite element model of a storage tank that considers soil-structure dynamic interaction and fluid-solid coupling effect is established in this study. Artificial boundaries are adopted to simulate the wave radiation effect of the semi-infinite foundation. The seismic wave input method based on the substructure of the artificial boundary is used to input the seismic waves into the numerical model. Then, the influence of soil-structure dynamic interaction on the seismic response of the liquid storage tank is investigated. The results show that the natural frequencies of the storage tank-liquid coupled system become lower when the soil-structure interaction is considered. Compared with the model without considering soil-structure interaction, there are additional vibration modes in which the soil participates. Affected by the different spectral components of the incident seismic waves and the change of the natural frequencies of the liquid storage tank, soil-structure interaction has different influences on the peak seismic response under different incident seismic waves and liquid storage volumes. For the subsequent responses after the peak seismic response, the scattered waves generated by the interaction between the foundation and the storage tank propagate outward and are eventually absorbed by the artificial boundaries when considering soil-structure interaction. It results in a rapid attenuation of the subsequent vibration amplitudes of the storage tank and the internal liquid.