Development and Application of a Generalized Potential Slip-Surface Model for Complex Slopes under the Principal Stress Direction Deflection Mode

Under complex geological settings, slope failure modes are often irregular and noncircular. The characteristics of the critical slip surface are governed not only by contrasts in the strength of rock/soil mass but also by the distribution of stresses along the prospective sliding path, demanding models that couple morphology with mechanics. This study presents a general modeling framework that constructs potential slip surfaces consistent with stress trajectories and strength criteria. Exploiting the link between stress state and shear failure orientation, a Taylor-series regression captures local deflections of principal stress directions, generating slip surfaces of arbitrary shape. A coupled solution strategy integrates an improved tensile–shear strength criterion with a limit-equilibrium formulation based on stresses, thereby ensuring mechanical consistency. To locate the governing failure mechanism, this study optimizes Taylor expansion parameters using a genetic algorithm that targets the minimum slope factor of safety. Validation on canonical benchmarks—homogeneous slopes exhibiting circular failure and stratified slopes producing composite, noncircular surfaces—shows close agreement with the existing results and captures stress-compatible sliding morphologies. The approach links slip-surface morphology, stress state, and strength parameters, overcoming limitations of traditional models in adaptability and mechanical coherence, and provides a practical, computationally efficient tool for stability assessment under complex geology.