Four-Modulus Incremental Nonlinear Model of Granular Soils Considering Stress Path and Particle Breakage.

The mechanical properties of granular soils are significantly influenced by stress paths and particle breakage. In this study, a four-modulus incremental nonlinear model that incorporates the effects of the stress path and particle breakage was established based on an analysis of triaxial compression test results conducted on calcareous sands subjected to varying stress paths. A mathematical expression for this model and the process of determining its parameters was proposed. Subsequently, the model was experimentally verified. Our findings revealed that the isotropic compression consolidation volumetric strain modulus exhibited a curvilinear relationship with the average effective principal stress, whereas it demonstrated a linear correlation with the relative breakage index. Furthermore, a four-parameter nonlinear model was constructed, integrating the dilatancy equation to consider stress path effects and establishing a functional relationship between the stress ratio and shear strain. By comparing the experimental results with the calculated results for calcareous sands and rockfill materials, the model effectively simulated the stress ratio-axial strain behavior of granular soils under different stress paths. However, it failed to fully capture the volumetric strain-axial strain characteristics of granular soils after reaching the peak stress ratio. Therefore, further research is necessary to develop a more comprehensive correction method for incremental nonlinear models. [ABSTRACT FROM AUTHOR]