Numerical and Experimental Investigation of the Argillaceous Sandstone Mechanical Properties by the Discrete Element Method

In this paper, the triaxial compression test of the argillaceous sandstone is carried out by using the digital control electrohydraulic servo testing machine (RMT-150C). Based on the results of the macroscopic test, we use the three-dimensional particle flow code to simulate the macroscopic stress and deformation characteristics of the argillaceous sandstone under the three-dimensional stress condition, and the meso-macroscopic parameters are connected to simulate the different porosity, The coefficient of friction, the bond strength on the specimen, and further improve the study of argillaceous sandstone. The results show that the simulation results of particle flow program are in good agreement with the macroscopic experiments, but the strength is slightly lower than the experimental value. The strength of argillaceous sandstone increases with the friction coefficient between the particles and the bond strength at the contact point. The strength decreases with the increase of the porosity ratio, but the effect is not as obvious as the friction coefficient. The significance of the study is to reveal the factors that reveeal the strength of coarse-grained soil from a microscopic point of view, breaking the limitations of conventional triaxial test.