Particle Shape Distribution Effects on the Triaxial Response of Sands: A DEM Study

It is widely recognised that particle shape influences the mechanical response of granular materials. Rolling resistance elasto-plastic contact models are frequently used to approximate particle shape effects in simulations using the Discrete Element Method (DEM). Such contact models require calibration of several micro-parameters, most importantly a rolling resistance coefficient. In this work, the value of rolling resistance is directly linked to true sphericity, a basic measure of grain shape. When shape measurements are performed, this link enables independent evaluation of the rolling resistance coefficient. It does also allow the characteristic shape variability of natural soils to be easily taken into account. In this work, we explore the effect of shape variability on the triaxial response of sand. It is shown, using realistic values of shape distributions, that shape variability significantly affects observed triaxial strength.