DISCRETE ELEMENT MODEL PARAMETERS TO SIMULATE SLOPE MOVEMENTS

Abstract

Discrete Element Method (DEM) is a numerical technique that uses particulate mechanics in
simulating the discontinuous behavior of particulate materials. DEM presents the advantage of modelling those
materials in a particulate level allowing specifications of particle geometry including how their contacts interact.
However, identifying microparameters that can accurately simulate the behavior of particulate materials is
challenging. This paper presents the calibration of the microparameters of materials used in an earthfill dam
that experienced slope movements. The main components of the earthfill dam under study were clay, for the
core and blanket, and rockfill materials, for the protective shell. Linear parallel-bond model (LPBM) was used
to describe the interactions between clay particles. Microparameters involved with the LPBM were particle
stiffness, friction coefficient, bond strength, and bond stiffness. A triaxial test DEM model was developed to
calibrate the clay microparameters, and it was successful in simulating the measured macroscopic peak and
critical state behavior of clay materials. Rolling resistance linear model was used to describe the interactions
between rockfill particles. Microparameters associated with the rolling resistance linear model were particle
stiffness, friction coefficient, and rolling resistance coefficient. Large-scale direct shear test was simulated to
calibrate rockfill microparameters, and it was able to capture the measured macroscopic shear behavior of
rockfill materials. Calibration methodologies performed were successful in identifying appropriate
microparameters for both rockfill and clay materials. The calibrated microparameters are beneficial in the
development of a DEM model that can analyze movements and landslides in the vicinity of the earthfill dam
or other earthfill dams built with similar materials.