Stability analysis of soil slope based on deformation reinforcement theory

Abstract

The traditional rigid-body limit equilibrium method cannot provide actual stress distribution in slope stability analysis, neither finite-element-based strength reduction method could accurately identify convergence points in related nonlinear calculation. Deformation Reinforcement Theory (DRT) is elaborated and developed with a definition of instability that an elasto-plastic structure is not stable if it is unable to satisfy simultaneously equilibrium condition, kinematical admissibility and constitutive equations under given external loads. It stated that Plastic Complementary Energy (PCE) and unbalanced forces can be used to evaluate the stability of the slope and indicate reinforcement if required. FEM expression of DRT was deduced and implemented in TFINE, a nonlinear three dimensional finite element method program, and furthermore, successfully applied in slope stability computation and analysis. The results of classic case studies showed that many key issues in slope analysis could be well solved within the framework of the DRT. The stability of the slope can be determined by the curve of the PCE norm vs. Strength Reduction Factor (SRF). The unbalanced-force derived by elasto-plastic FEM analysis could be the basis of reinforcement design and evaluation.