Kinematics and internal deformation of granular slopes: insights from discrete element modeling

Abstract

The kinematics and internal deformation of a failure mass during the flow-like moving off a slope were monitored and quantified with the particle flow method in this study. Two kinds of cases were investigated, noncohesive and cohesive granular slopes. Three different internal friction angles and cohesive strengths were considered to systematically investigate their effect on the kinematics and internal deformation of the failure mass. We analyzed the movement within the failure mass and concluded that the mass moves downwards in an undulating pattern. The slope surface topography changes from a straight line to curved lines with slope breaks in a convex geometry. In addition, dilatation within the failure mass, which deforms internally and heterogeneously, is strongly dependent on its mechanical properties. A larger mass moves downslope, and the mass moves faster and further in the model with lower internal friction and cohesion. The internal friction and cohesion have a positive impact on porosity and two-dimensional (or volumetric in 3D) strain within the failure mass.

Validation of DEM prediction for granular avalanches on irregular terrain

“…[], Cleary [], Staron [], Thompson et al . [], and Liu and Koyi []. Two‐dimensional DEM is commonly limited to studying fundamental problems in highly simplified configurations; however, some quasi‐realistic avalanche scenarios have been attempted.…”

“…Calculated runout distances were consistent with distances obtained through field data and particularly demonstrated the dependence of Journal of Geophysical Research: Earth Surface 10.1002/2014JF003331 runout distance on landslide volume. More recent investigations of fundamental mechanics and runout distances using two-dimensional DEM are given by Okura et al [2000], Cleary [2007], Staron [2008], Thompson et al [2009], and Liu and Koyi [2013]. Two-dimensional DEM is commonly limited to studying fundamental problems in highly simplified configurations; however, some quasi-realistic avalanche scenarios have been attempted.…”

Granular flow on a rotating and gravitating elliptical body

“…We note that DE simulations for terrestrial landslides and avalanches have been performed previously by many researchers, e.g. Cleary (2007), Liu & Koyi (2013). However, similar studies on small rotating, aspherical, extra-terrestrial bodies are not available.…”

Step-path failure of rock slopes with intermittent joints

“…To simulate the movement of rock blocks and granular assemblies in complex geological materials, many numerical methods based on discontinuum mechanics, such as the discrete element method (DEM), discontinuous deformation analysis (DDA), and NMM, have also been widely applied (Cundall and Strack 1979;Chihsen et al 1996;Eberhardt et al 2004b;Hatzor et al 2004;Ma et al 2010;Ning et al 2011Ning et al , 2012bLiu and Koyi 2013). The 2D Particle Flow Code (PFC) based on the principle of the DEM represents a rock mass as an assemblage of bonded rigid circular particles.…”