Influence of fabric anisotropy on stability and failure mechanism of slopes: insights from an anisotropic Mohr–Coulomb model

Natural soil deposits often exhibit inherent fabric anisotropy, which can significantly influence their mechanical behavior and the performance of geostructures. However, conventional slope stability analyses typically rely on isotropic failure criteria or oversimplified methods, and there remains a lack of effective approaches that can accurately capture the anisotropy of soil deposits. To address this gap, this study investigates the stability and failure mechanisms of slopes in anisotropic soils using finite element analysis. The simulations employ a Mohr–Coulomb model enhanced by anisotropic critical state theory, capable of capturing several key features of soils, such as state-dependent dilatancy, strain-softening behavior, and the evolution of fabric anisotropy. A series of numerical analyses is performed under various fabric orientations and slope inclinations. The results highlight the pronounced impact of fabric anisotropy on the stability of slopes. Comparisons with predictions from an isotropic model reveal that neglecting fabric anisotropy can lead to a significant overestimation of slope stability, underscoring the importance of incorporating fabric anisotropy in practical design.