Limit Equilibrium Method 3D Slope Analysis: Safety Factor and Failure Mode Effects of Slope Height and Angle

The safety of slopes is primarily determined by various elements, including geometry and soil conditions. The factor of safety (FS) might vary considerably based on the soil/rock composition and the form of the slope. Knowing the way variations in the height and angle of a slope affect the safety factor is crucial for developing an effective plan to improve slope stability. A thorough investigation of the impact of geometric shapes on slope stability requires the use of three-dimensional (3D) slope stability analysis. This type of analysis applies to all slopes, including those that do not meet the plane-strain requirements. To determine the 3D safety factor, tests were carried out on sandy soil slopes with specified soil characteristics, while altering the combinations of slope height (12 m, 6 m, 3 m) with angles (30.96°, 25.64°, 21.8°, and 18.77°). The height and angle of each slope were recorded to determine the specific types of slope failure. However, the safety factor increases at varying rates as the slope’s height reduces. Conversely, a decrease in slope angle has an almost linear effect on the safety factor, causing it to increase. For slopes smaller than 6.0 m in height and corresponding slope angles of 30.96°, 25.64°, 21.8°, and 18.77°, respectively, base failure is the most likely form of failure. Toe slide is the predominant kind of slope collapse observed on sandy soils when the height exceeds 3 m.