TITLE:
Comparative Stability Analysis of Slopes in Gouache (West-Cameroon) Using Finite Element and Limit Equilibrium Methods
AUTHORS:
Willy Chance Guimezap Kenou, Vladimir Willianov Keubou Tatapzia, Ulrich Audrey Kamdem Dassi, Bertile Ilalie Manefouet, Thierry Constant Nie Noumsi, François Ngapgue
KEYWORDS:
Embankment, Safety Coefficient, Stabilization, Finite Element Methods, Limit Equilibrium Methods, C-φ Reduction
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.7,
July
31,
2026
ABSTRACT: This study investigates the stability of three slopes in the Gouache area and its surroundings using both the Finite Element Method (FEM) and Limit Equilibrium Methods (LEM) to enable comparative analysis and potential design of slope reinforcement. Stability analyses were conducted based on the Mohr-Coulomb model and the reduced C-φ approach, with field and laboratory work undertaken to determine the necessary geotechnical parameters. The studied slopes are characterized by significant heights (exceeding 15 m) and moderately steep inclinations (over 40˚). Laboratory analyses show an average fine fraction of 51.81%, a liquid limit of 54.18%, a plastic limit of 35.58%, and a plasticity index of 18.6%. The optimal water content is 19% with a corresponding dry density of 1.66 g/cm3 at Proctor optimum, and an average CBR index of 2.53%. According to Casagrande’s plasticity chart, the soils at point 1 of slope 1 are classified as low-plasticity silts, while point 2 of slope 1 and slopes 2 and 3 are high-plasticity silts. HRB classification identifies all soils as clayey. The soils are over-consolidated with an average cohesion of 43.33 kPa and an internal friction angle of 32.28˚. Stability coefficients obtained using Plaxis are 1.460, 3.815, and 3.146 for slopes 1, 2, and 3, with maximum displacements of 0.335 m, 26.48 m, and 15.85 m, respectively. Limit Equilibrium analyses using GeoStudio yield factors of safety for slope 1 ranging from 0.939 to 0.997 depending on the method, for slope 2 from 2.125 to 2.177, and for slope 3 from 1.654 to 1.702. These results indicate that slope 1 is unstable and potentially hazardous, whereas slopes 2 and 3 are stable.