Stability Analysis of Anchor-Reinforced Soil Slopes with Taylor’s Stability Chart

Abstract

The stability of earth slopes can be enhanced by introducing an anchoring system. The factor of safety of an anchor-reinforced slope is one of the essential items required to evaluate stability. This parameter can be predicted using limit equilibrium and numerical approaches by relevant software. Taylor’s stability chart has been frequently used to estimate the factor of safety of an unreinforced homogeneous cohesive-frictional soil slope. An analytical expression was developed in this study based on the friction circle method by which the factor of safety of anchor-reinforced slopes can be predicted using Taylor’s chart. The anchor-reinforced slope considered in the analysis consisted of homogeneous cohesive-frictional soil. The analyses were carried out considering different slope inclinations, anchor loads, anchor orientations, and slip circles. An illustrative example explained the procedure for finding the factor of safety and showed how the developed method could be used by practicing engineers. A comparison between the factor of safety estimated by Taylor’s chart and the limit equilibrium method using SLIDE indicates a good agreement. An anchoring system can improve the stability of earth slopes. The safety factor of an anchor-reinforced slope is the most critical design parameter as it reflects whether the slope is stable against driving forces. In geotechnical engineering, the factor of safety can be computed using an analytical/numerical approach, based on which relevant commercial software programs have been developed. These software programs might not be available to everyone. More importantly, they often require parameters of soil that need complex tests to be found, making their use unattractive for practicing engineers. The factor of safety of plain slopes can be found using Taylor’s stability chart, which is widely used in practice due to being convenient. This study presents a method through which the factor of safety of each potential slip surface in an anchored reinforced slope can be determined using Taylor’s stability chart. According to the approach, an anchored slope is equalized with a plain slope having a greater value of internal soil friction angle. Then, the factor of safety of equalized plain slope is determined using Taylor’s stability chart.