A Surrogate Model for Stability Assessment of Two‐Layered Cohesive Slopes

ABSTRACT This paper introduces a novel surrogate model for rapid stability evaluation of two‐layered cohesive slopes under undrained conditions. The model eliminates the need for iterative calculations and slip surface searches, allowing for fast and accurate stability assessments without reliance on advanced numerical tools. The formulation is derived from an extensive parametric study using the Morgenstern–Price limit equilibrium method and is expressed through two physically meaningful dimensionless parameters: a stability number and a strength‐contrast ratio . These parameters directly govern the factor of safety, while a critical strength ratio delineates the transition between shallow (upper‐layer) and deep (two‐layer) failure mechanisms. The model is validated against SLOPE/W benchmarks and independently corroborated using Slide2 (multiple LEM variants) and PLAXIS 2D (FEM), showing high accuracy ( R ² ≈ 0.999) and low error (92% of predictions within ±5%) across 384 slope configurations. Two‐ and three‐dimensional stability charts are provided for immediate visualization and practical use. As a dimensionless, non‐iterative surrogate, the model offers high computational efficiency and mechanistic insight, effectively bridging classical stability charts and advanced numerical methods for preliminary design, parametric exploration, and large‐scale slope screening.