Abstract: In this lecture, Dr. Han will present results of recent studies on the response of non-displacement single piles and pile groups in sand using both numerical and experimental approaches. With the use of an advanced, two-surface-plasticity constitutive model and careful mesh refinement, the 3D Finite Element (FE) analysis successfully captures the localization of strains and shear band development along the pile shaft and near the pile base. The study aims to build the connection between the local micro behavior of soil elements and the global macro pile-soil response upon axial loading. In addition, axial load tests were performed on model piles pre-installed in sand samples prepared in a large-scale calibration chamber with Digital Image Correlation (DIC) image capabilities to obtain the displacement and strain fields in the sand during loading. The DIC image analysis enables the visualization of the complex boundary value problem, provides validation benchmark for numerical modeling, and advances the understanding of resistance mobilization mechanisms for non-displacement piles.