Yazoo clay soil is expansive in nature, and extended over central Mississippi, Alabama and Southern Louisiana. Shallow slope failures are frequent in embankments constructed on expansive Yazoo clay in Mississippi due to the rainfall volume and climatic variation. The current study investigates the effect of rainfall over the factor of safety of fill slopes constructed with Yazoo clay soil using the finite element method (FEM). The historical rainfall pattern of Mississippi obtained from the National Oceanic and Atmospheric Administration (NOAA), is evaluated at different intensities (2 to 50 mm/h), and durations of rainfall (30 min to 7 days) with the data being, based on a return periods of 50, 100, and 500 years. Three fill slopes were constructed using Yazoo clay soil, with a slope ratios of 2H: 1V, 3H: 1V, and 4H: 1V. The rainfall pattern is applied over the top boundary of the slope in Plaxis, using flow analysis. The preliminary investigation results indicated that rainfall water infiltrated the top part of the slope, near the crest, resulting in the reduction of both the matric suction and the factor of safety of the slope. Moreover, the factor of safety of the slope is directly influenced by the total rainfall volume, regardless of the intensity and duration.
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