A New Approach for Evaluating the Soil Slope Reinforcement Tensile Forces Using Limit Equilibrium Methods

Limit equilibrium methods have been extensively used in the design of reinforced soil structures using various types of failure surfaces. A significant problem in limit equilibrium analysis of reinforced soil is the need to know the force at each reinforcement layer in the limit state. Limit equilibrium analysis with log spiral failure mechanism has been employed to locate the critical failure surfaces emerging at or above the toe and to study the behavior of geosynthetic-reinforced soil slopes. This paper describes a numerical procedure, using limit equilibrium methods, to evaluate the distribution of the soil slope reinforcement tensile forces. Both, log spiral and circular slip surfaces are considered. The effect on the required tensile forces of the target safety factor value, the ratio of the mobilized soil shear strength, and the reinforcement layer spacing are examined. Results show that the distribution of reinforcement tensile forces is dependant on reinforcement layer spacing; however, the total reinforcement force is not. The total reinforcement force required to ensure equilibrium is strongly dependant on the target safety factor value and the ratio of the mobilized soil shear strength. Modified Bishop Method with circular failure surface and Shiwakoti-Leshchinsky log spiral failure surface led to comparable results.