Regularization effect of peridynamic horizon on strain localization and soil slope instability analysis

Abstract

Soil slope stability is significant to the safety of various geotechnical engineering structures, and the instability simulation of soil slope inevitably involves the shear band evolution. To avoid the mesh-dependence dilemma of traditional numerical methods in simulating shear band evolution, the present study develops a non-ordinary state-based peridynamics (NOSB PD) corresponding to the elastoplastic constitutive relationship with Drucker-Prager (DP) yield criterion. Significantly, the peridynamic horizon is a crucial parameter that effectively solves the mesh-dependence dilemma. A series of uniaxial compression simulations of soil block is then conducted to demonstrate the numerical accuracy and mesh independence of NOSB PD. Moreover, the relationship between shear band width and peridynamic horizon is quantitatively provided. Regarding the peridynamic (PD) horizon as a material parameter, this relationship provides a way to select the horizon size and discretization according to the shear band width of soils. Besides, the strength reduction method is embedded into the peridynamic framework to conduct the instability analysis of intact and defective soil slopes. The safety factor (FOS) is sensitive to the weak region at the slope toe. The present research somewhat provides constructive guidance for practical engineering that the soil quality and reinforcement at the slope toe deserve more attention.