A Novel Method for Stability Analysis of Weakly Inclined Subgrade by Centrifuge Model Test and the Finite-Element Method

The stability analysis of a weakly inclined subgrade is a crucial topic of geotechnical engineering. This work established a novel method based on the Swedish method to solve the stability analysis of a weakly inclined subgrade. Centrifuge model tests were used to examine the failure mechanisms of a weakly inclined subgrade. Then, a series of two-dimensional (2D) and three-dimensional (3D) numerical simulations analyses were performed to find the influencing factor affecting the weakly inclined subgrade's stability. According to the experimental and numerical simulation results, there were obvious differences in the instability failure mode between the weakly inclined and the weakly horizontal subgrades. In the novel method, the mechanism that caused the instability of the weakly inclined subgrade was studied by introducing influential force and additional force. While the influential force suggested the impact of the potential difference, the additional force indicated the gravity impact emanating from the lateral embankment. After contrasting the results in the engineering example, the proposed method's viability was confirmed. The proposed method was found more suitable for performing the stability analysis of a weakly inclined subgrade than the traditional slice methods.