Numerical Study On Slope Stability By General Particle Dynamics

Landslide is one of the most threating natural catastrophe and the stability of a slope is closely related to the safety of property and lifes,which makes the stability evaluation of slope become a signficantly important research area of geomechanics and rock mechanics.During the past several decades,limit equilibrium methods and finite-element menthod are the standard method and widely employed for most slope stability analyses.However,slope instability often comes out together with large deformation and intensive discontinuous failure of soil,which is difficult for either FEM or LEMs to deal with,as the excess distortion of FEM mesh induced by large deformation may lead to instability or non-convergent of the calculation.In this study,in order to solve this problem,a mesh-free Lagrangian scheme based method,General particle dynamics,which is modified fromsmoothed particle hydrodynamic,is adopted for stability analyses of slope,as well as to simulate the big deformation and post-failure process of rock mass.Firstly,a series of numerical solutions of soil accumulation,rectangular non-cohesive and cohesive soil collapse,small-scale slope and stepped slope,are conducted to validate accuracy of the elastic-perfectly plastic model with D-P yield criterion when dealing with stress-stain and displacement of soil.These solutions have also presented the realibility of the elastic-perfectly plastic GPD model for stability evulations as it can clearly capture the shear band by contour plot of accumulated plastic strain when reaching soil reached its shear-resistant strength,as well as the critical slip surface.These results have also show the ability of the GPD model of dealing with large deformation and post-failure behavior of soil.After the validation work,this elastic-perfectly plastic model is used for the stability evaluation of large-scale slopes.The Shear strength reduction technique with D-P yield criterion is applied to calculate the safety factors 9 large step-shape slopes.The failure mechanicsms including toe failure mechanicms and deep-seated failure mechnacism,as well as the reason for the fluctuation occurred on the curves of displacement-time are discussed.Moreover,frictional interaction algorithm is complemented to further develop the ability of the elastic-perfectly plastic GPD model for the solution of progressive failure of largescale stepped slope,slope containing joints and slope with a simplified bolt-rock model,respectively.