(1. State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering，China University of Mining and Technology，Xuzhou，Jiangsu 221116，China；2. School of Resources and Geosciences，China University of Mining and Technology，Xuzhou，Jiangsu 221116，China；3. College of Geology and Environment，Xi?an University of Science and Technology，Xi?an，Shaanxi 710054，China)
Abstract：To quantitatively analyze the grain size effect of the compression characteristics of granites under loading，a three-dimensional grain-based model based on particle flow code is used to restore the internal structure of granites. The whole force chain network of the sample is divided into multiple levels. The value，number and orientation distribution of force chains in intragranular structures and intergranular structures are quantitatively explored. The grain size effect on uniaxial compressive strength，micro-cracking behavior，load-bearing capacity and fracture resistance of various structures is quantized in force chain point of view. The results show that when the number of contacts is basically unchanged，the decrease in the general force chain(GF) number and the increase in the microcrack number have a good correlation. The orientation distributions of various GFs are relatively uniform. The overall level of the force chain network increases with the increase of RG. The main orientation distribution of the high-strength force chain(HF) is consistent with the loading direction and is orthogonal to that of cracks. The number of HF can well characterize the macroscopic mechanical properties of the sample. The load-bearing capacity of intact minerals and intergranular structures increases with the increase of RG，and the variation range is proportional to the micro-tension strength of internal contacts. The number of HF required to produce a single crack in intact mineral structures increases as RG increases，that is，the fracture resistance increases，but the fracture resistance of intergranular structures do not change significantly versus RG.
张 涛1，蔚立元1，苏海健1，高亚楠1，贺 虎2，魏江波3. 基于多级力链网络分析的花岗岩压缩特性的矿物尺寸效应研究[J]. 岩石力学与工程学报, 2023, 42(8): 1988-2003.
ZHANG Tao1，YU Liyuan1，SU Haijian1，GAO Yannan1，HE Hu2，WEI Jiangbo3. Investigation on the grain size effect of the compression characteristics of granites based on the multi-level force chain network. , 2023, 42(8): 1988-2003.
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2023, Vol. 42 
