DEM Simulation of Mechanical Behavior of Cemented Angular Sand under Isotropic Compression Test

The mechanical behavior of cemented sand is different from that of uncemented sand because of the presence of bonds between particles. In this study, the effect of bond strength on the mechanical behavior of cemented sand under isotropic compression test is investigated by using a numerical method called as Discrete Element Method (DEM) in a two-dimensional space. DEM is a powerful numerical tool by which, each particle is considered as a rigid body, and the equilibrium condition is satisfied by applying accelerations and displacement along with applied forces from adjacent particles. The novelty of this study in comparison to similar works is to consider the angular geometry of particle shape rather than supposing circular. The particles are connected to each other To simulate the cementation agent. For the simulation of bonds, a bond contact model is defined by considering tension, compression, and shear strengths; the tension and shear resistance of bonds are assumed to be equal. In this model, it is essential for particles to have physical contact and overlap to consider that they are bonded to each other. For the simulation of isotropic compression tests, the samples are loaded isotropically up to 60 MPa under different stress levels. The results indicate that with an increase in the bond strength, the sample resists higher against volume reduction, and also, primary and gross yield stresses increase. Results show that when a cemented sample reaches the primary yield point, the rate of broken bonds increases. The pressure that is carried out by bonds increases as the volumetric strain augments. In this research, the results are validated by existing experiments in the literature.