A coarse-grained bonded particle model for large-scale rock simulation
Chengshun Shang, Liping Li, Kaiwei Chu, Zongqing Zhou, Guillermo Casas, Wenfeng Tu, Yuxue Chen, Shangqu Sun
Abstract
For solving the computationally intensive problem encountered by the discrete element method (DEM) in simulating large-scale engineering problems, it is essential to establish a numerical model that can effectively simulate large-scale rocks. In this study, the coarse-graining effect of a linear-Mindlin with bonding model was studied in the unconfined compression strength (UCS) and Brazilian tensile strength (BTS) tests. We found that the main reason for the coarse-graining effect of the BTS tests is that the type I fracture toughness is positively correlated with the size of the particles. Based on the results analysis and fracture mechanics, the coarse-grained (CG) modeling theory was combined with a bonded particle model (BPM) for the first time and a coarse-grained bonded particle model (CG-BPM) was developed, which can be effectively used to model the tensile strength of large-scale rocks with different particle sizes. The excavation damage zone (EDZ) in an underground research laboratory (URL) was selected as an application case, which shows that the coarse-grained bonding model presented in this paper is more accurate and reliable than the traditional one in large-scale rock simulation, at least in the scenario where tensile failure is dominant.