Abstract: The stability of the slope at a large earthwork disposal site in Guangxi Province is analyzed through the on-site investigation and the preliminary geological data. The lithology and geological structure of the disposal site are identified. The laboratory direct shear tests provide the mechanical properties and strength parameters of the soil in both natural and saturated states. Based on all above information, the drainage capacity of the ditches in the disposal area and the stability of the slope under different operational conditions are studied using standard verification and limit equilibrium methods. The results show that the surface drainage capacity of the ditches in the disposal area is 15.93 m³·s^-1, slightly higher than the calculated peak flood flow of 14.31 m³·s^-1 in the catchment area, with a safety margin of about 13%. It is recommended to plant grass for vegetating in the disposal site and regularly inspect the integrity of the drainage ditches. The minimum safety factor values for the slope under the normal operating conditions, special operating conditions I, and special operating conditions II are 1.56, which is higher than the standard value. This indicates that there will be no local or overall deformation failure in the waste disposal area, nor will there be overall failure along the original ground surface interface. The potential sliding surfaces of the slope mostly appear at the top of the first-level platform and the retaining wall. Daily inspections should pay special attention to deformation and cracks at the top of the retaining wall and the first-level platform.

Key words: Slope of Soil Disposal Site, Stability Analysis, Drainage Verification, Strength Testing, Limit Equilibrium