A rigorous analytical approach to predicting the load-settlement behavior of axially loaded piles embedded in sands incorporating the SANISAND model

The paper presents a rigorous analytical approach to predicting the load-settlement behavior of axially loaded piles embedded in sandy soils, adopting the advanced SANISAND model. The problem of the soil state around the pile during loading is formulated as a system of first-order ordinary differential equations, which can be solved as an initial value problem. The derived load-settlement (t-z) curve is then implemented into the load-transfer method to determine the pile's load-settlement behavior in sands and the deformation mechanism of the soil around the pile during axial loading. To verify the proposed analytical approach, a FEM simulation is performed with a user-defined subroutine, demonstrating its capacity to capture the dilatancy behavior of sands as the pile moves downwards. Additionally, a parametric analysis is conducted to assess the influence of the initial void ratio on the stress-strain relationship of the sandy soil around the pile during the loading process. The proposed analytical approach is also compared with a well-established finite-element model and a centrifuge test. The results indicate that the present approach can well predict the elastoplastic load-settlement response of the pile and reflect important phenomena observed from pile tests.