Efficient Finite Element Modeling of Initial K0 Geostress and Shear-Slide Stability in Sloping Ground

Reliable initialization of in situ K₀ K 0 stresses and efficient stability analysis are fundamental to robust finite-element modeling of infinite slopes. Yet, existing modeling schemes either apply gravity loading with an indirect K₀-ν K 0 - ν mapping that is not mechanics-consistent for sloping ground, or require large computational domains that are expensive for repeated analyses. In this study, an efficient FEM framework is developed that retains the gravity load procedure (GLP) and addresses its stress-initialization limitation for homogeneous infinite slopes. Specifically, a closed-form coupling of Poisson’s ratio components is derived within a transversely isotropic elastic formulation, in which slope cross-anisotropy arises from stress-induced anisotropy. This coupling enforces target K₀ K 0 -type geostress states in sloping ground, without using the conventional horizontal-ground K₀-ν K 0 - ν relation. The formulation is implemented in a compact periodic unit-block FEM model (Geometry I, L/H = 0.2). It is combined with strength-reduction using an elastic–perfectly plastic Mohr–Coulomb model for shear-slide factor-of-safety (FOS) assessment. Results are evaluated against analytical infinite-slope solutions and conventional large-domain FEM simulations (Geometry II, L/H = 32) performed using COMSOL Multiphysics and PLAXIS 2D. The proposed model reproduces analytical K₀ K 0 stress profiles across tested slope angles and pore-pressure ratios. It avoids spurious yielding during geostress initialization and provides FOS predictions in close agreement with analytical solutions under both dry and seepage-parallel conditions. Compared with the large-domain approach, it delivers substantially improved efficiency (at least ~ 4 × shorter runtime in tested cases) with orders-of-magnitude fewer degrees of freedom, while preserving the expected slope-parallel failure mechanism. The effects of slope angle, pore-pressure ratio, and stress-induced anisotropy are investigated, and the results are discussed.