Pile foundation in alternate layered liquefiable and non-liquefiable soil deposits subjected to earthquake loading

Pile foundations are still the preferred foundation system for high-rise structures in earthquake-prone regions. Pile foundations have experienced failures in past earthquakes due to liquefaction. Research on pile foundations in liquefiable soils has primarily focused on the pile foundation behavior in two or three-layered soil profiles. However, in natural occurrence, it may occur in alternative layers of liquefiable and non-liquefiable soil. However, the experimental and/or numerical studies on the layered effect on pile foundations have not been widely addressed in the literature. Most of the design codes across the world do not explicitly mention the effect of sandwiched non-liquefiable soil layers on the pile response. In the present study, the behavior of an end-bearing pile in layered liquefiable and non-liquefiable soil deposit is studied numerically. This study found that the kinematic bending moment is higher and governs the design when the effect of the sandwiched non-liquefied layer is considered in the analysis as opposed to when its effect is ignored. Therefore, ignoring the effect of the sandwiched non-liquefied layer in a liquefiable soil deposit might be a nonconservative design approach.