Study of the Effect of Micro-Parameters of Intragranular Contacts on the Mechanical Behavior of Granite Based on Three-Dimensional GBM and Force Chain Network

Based on the three-dimensional Grain-Based Model, the influence of the micro-strength and micro-modulus of the intragranular structures on the mechanical behavior of the model was explored from the point of force chains. The force chain characteristic of the sample is quantified, and then the force chain characteristics of the samples were quantitatively analyzed to reveal the evolution mechanism of the overall mechanical parameters and fracture characteristics of the samples when the micro-parameters of the intragranular contact changed. It is found that with the increase in contact micro-strength, bonding can withstand a higher level of concentrated stress. In the loading process, the slippage between particles occurs, but the overall slippage distance decreases due to the decrease in the number of fracture bonds, which leads to an increase in the strength and deformation resistance of the sample. With the increase in the contact micro-modulus, the allowable distance of particle slippage decreases. The lower force chain can make the slippage distance of particles reach the threshold value, and the external load easily causes the generation of cracks. Therefore, the overall strength of the sample decreases, and the overall deformation of the sample decreases. The research results can provide some references for the construction of the heterogeneity model, quantitative analysis of the force chain network, and calibration of model micro-parameters.