Lateral Behavior of a Large Pile Group Supporting an LNG Tank

Large pile groups (≥=100 piles) are often used to support liquefied natural gas (LNG) tanks to resist not only large vertical structural loads but also significant lateral loads from earthquakes or hurricanes. In general, the design of a large pile group follows standards or prevalent methods that are established based on field or centrifuge test results for a small pile group (≤=25 piles). This does not recognize that lateral group effect of a large pile group is more pronounced than that of a small pile group, and the use of the recommended group reduction factors for a small pile group can be unsafe for the design of a large pile group, in particular for a pile foundation with ≥= 1,000 piles (such as an LNG tank foundation). This study employed a series of 3D continuum finite-element analyses to investigate lateral responses (bending moment, shear force, and lateral displacement) of piles in square pile groups from 3 × 3 to 40 × 40 as well as in circular pile groups supporting LNG tanks. The results were used to examine the difference of lateral responses of piles between single isolated piles, small pile groups, and large pile groups, which would allow for a better understanding of lateral behavior of a large-scale pile foundation supporting an LNG tank.