Interaction of Saturated Granular Soils with Pile Foundation: A Micro-Mechanical Study

Saturated granular soils exhibit complex response mechanisms in the presence of subsurface structural elements such as pile foundation. Some of these mechanisms are heavily dependent on the particulate discrete nature of these soils and are still not fully understood. A coupled continuum-discrete model is used in this study to analyze the response and interaction of saturated granular soils with a pile foundation. A Lagrangian discrete element method (DEM) formulation is used to model the soil solid phase as an assemblage of particles. The fluid phase is idealized using an Eulerian formulation based on averaged Navier-Stokes equations. The Bernoulli beam theory and finite element (FEM) technique are employed to model the pile structural elements. The responses of soil fluid and solid phases and the pile structural elements are fully coupled. Numerical simulations were conducted to investigate the dynamic response and interaction of a sloping deposit of a saturated granular soil with a pile foundation during liquefaction and lateral spreading. The conducted simulations provided valuable information on a number of salient response mechanisms.