Seismic performance of LNG tanks in deep soil site considering soil-foundation-structure interaction

Abstract

The seismic performance of liquefied natural gas (LNG) tanks is significantly influenced by Soil-Foundation-Structure Interaction (SFSI). It is essential to investigate the effect of the SFSI on isolated LNG tank, particularly on a deep soil site. This study aims to examine the impact of the SFSI on the seismic performance of an isolated LNG tank located on the deep soil site. The impact of foundation type, pile length, and the frequency content on the primary seismic responses of the LNG tank were thoroughly examined in this study. These seismic responses include the acceleration of the outer tank, the height of the sloshing wave, and the shear force and bending moment of the inner tank. Additionally, the seismic force along the pile foundation, such as shear force, lateral displacement, and bending moment, was also analyzed. The results indicate that for isolated LNG tanks, it would be dangerous without considering the SFSI, while for the pile foundation, it may be beneficial when considering the SFSI. The pile foundation types did not considerably affect the seismic response of the isolated LNG tank in the deep soil site. Additionally, the seismic response appears to be highly sensitive to the frequency characteristics of the seismic excitation, especially the low-frequency content.