Development and application of a nonlinear stress dilatancy model for geocell-reinforced soil via the FEM

Abstract

To address the ambiguities in current ontological models of geocell-reinforced soil and the limitations inherent in finite element analysis methods, a nonlinear stress dilatancy model (NSDM) encompassing geocell-reinforced soil was successfully formulated. This model is based on the interaction between the geocell and the infilled soil, which can consider the confining pressures provided by the geocells and the stress dilatancy model of the soil. A finite element method (FEM) implementation of the model was achieved via the User-defined Material (UMAT) subroutine interface provided by ABAQUS software. Validation of the model was achieved via triaxial tests on geocell-reinforced sand with varying relative densities, as well as reinforced foundation and retaining wall model tests. Concurrently, the model calculation results were compared and analyzed with those obtained from a conventional separated model, and an in-depth exploration of the sensitivity of the model's key parameters was carried out. The findings demonstrate that the UMAT subroutine of the model can accurately predict the reinforced sand triaxial test, the reinforced foundation model test and the retaining wall model test results. Compared with the reinforced soil-separated model, the model delineated in this paper is easier to construct and has markedly improved computational efficiency. Additionally, the model can capture failure within the geocell fill, thereby affording a more precise depiction in the near-failure stage. This research offers an efficient and practical novel methodology for numerical analysis within the domain of geocell-reinforced soil.