Analysis of Partially Saturated Clayey Slopes Using Finite Element Method

According to Bishop's equation of effective stress for partially saturated soils, matric suction can increase the effective stress that is subjected to negative pore water pressure. The shear strength of soil is controlled by the effective stress and, hence, the increase in shear strength that is due to soil suction can affect slope stability. This paper presents slope stability analysis that includes the effects of soil suction for partially saturated soils under different groundwater conditions.Using pore/fluid stress elements and appropriate soil water characteristic curve data for the soil properties, the soil was modeled by considering groundwater table fluctuations and negative pore pressure in partially saturated zones. This paper presents the outputs that were supported by the pore/fluid stress elements, which include the void ratio, pore pressure, equivalent plastic deformation, strength reduction factors, and vertical effective stress, and discusses the contribution of negative pore water pressure in the slope stability analysis and/or for reference in slope remediation design.