Revisiting Slope Stability Analysis Using Tension-Truncated Power-Law Yield Criterion

Abstract

Existing studies on slope stability have mostly been performed using the linear yield criterion without accounting for the true tensile strength of soils. However, soils generally exhibit marked nonlinearity in shear strength and practically negligible tensile strengths compared to theoretical estimates from the yield function. This research revisits the finite slope stability problem under plane strain conditions by employing a power-law (PL) yield criterion with a tensile strength cut-off. Here, a PL yield criterion is truncated with a circular stress envelope that tangentially encompasses the nonlinear PL yield function for a given uniaxial tensile strength. Unlike earlier studies, this research proposes a new horizontal slice-based rotational failure mechanism, and the solutions are rigorously determined within the upper bound plasticity theory by fully accounting for the variable nature of friction angles along the slip surface in a nonlinear bonded medium. The effect of pore-water pressure on the results is also investigated. The study shows that additional nonlinearity in the yield function, due to the tensile strength cut-off, can significantly influence the outcome of the stability assessment. The results of this study compared reasonably well with findings in the existing literature. The novelty of this study lies in presenting a new slice-based numerical solution procedure for investigating slope stability with variable friction angles and demonstrating the significant impact of tensile strength cut-off on stability assessment outcomes in nonlinear bonded soils.