Modeling Large‐Deformation Geotechnical Problems in Granular Soils: Integrating a Micromechanics‐Based Model With the Explicit Finite Element Method

ABSTRACT Large‐deformation problems in granular soils are of central importance in geotechnical engineering, as they govern the performance of foundations, retaining structures, and earthworks under extreme loading conditions. Reliable prediction of such phenomena remains challenging due to the complex material behavior and the occurrence of strain localization. To address this challenge, this study implements a micromechanics‐based constitutive model with a few parameters of physical meaning into an explicit finite element code, thereby bypassing the severe convergence difficulties often encountered in implicit finite element analyses. The validity of the approach was first examined through a series of benchmark problems, including a biaxial test and the settlement of a square footing. The model was then applied to three large‐deformation problems in which pronounced strain localization developed. Retaining walls displaced with and without rotation, corresponding to active and passive loading modes, generated shear band patterns consistent with experimental measurements and Discrete Element Method simulations. An axially loaded closed‐ended pile was also analyzed, with the computed load capacity showing good agreement with centrifuge test data. Finally, the method was applied to the analysis of a novel bucket foundation, further demonstrating its robustness in capturing complex large‐deformation behavior of granular soils. Overall, the results highlight the potential of micromechanics‐based multiscale modeling within the Finite Element Method as a reliable and versatile tool for geotechnical engineering practice.