离散元分层模型单轴压缩试验适用性宏细观分析  

Macro and Meso Analysis on Suitability of Discrete Element Layered Model for Uniaxial Compression Test

作　　者：陈龙 何志敏 温时雨 吴顺川 贺尧 CHEN Long;HE Zhimin;WEN Shiyu;WU Shunchuan;HE Yao(China Railway Development and Investment Group Co.,Ltd.,Kunming,Yunnan 650500,China;Faculty of Land Resources Engineering,Kunming University of Science and Technology,Kunming,Yunnan 650093,China)

机构地区：[1]中铁开发投资集团有限公司,云南昆明650500 [2]昆明理工大学国土资源工程学院,云南昆明650093

出　　处：《矿业研究与开发》2024年第11期118-127,共10页Mining Research and Development

基　　金：云南省高校科技创新团队支持计划项目(202105AE160023)。

摘　　要：在颗粒离散元法中,采用内外不同尺寸度(分层)建模法可以减少计算量,有效提高计算的精确度,进而对隧道、边坡等大尺度工程问题进行建模计算。虽然分层建模法在模型生成、接触分配等方面可行,但其在加载条件下的力学行为是否与常规模型相同、计算结果与室内试验的匹配程度仍是未知。从宏细观角度分析了岩石分层模型单轴压缩试验的有效性,探究外内层平均粒径比、内层模型尺寸对分层模型抗压强度的影响,并通过室内试验与模型计算结果进行对比。研究结果表明,岩石分层模型的分层结构不会对其在单轴压缩条件下的宏观力学性质产生异常影响,力在层交界面处可以正常传递,但分层结构会使模型吸收、储存、消耗更多的能量。分层模型单轴抗压强度随外内层平均粒径比的增大而增大,随着内层体积的增大,分层模型单轴抗压强度呈先增大后减小的趋势。采用分层模型匹配岩石试样的单轴抗压强度时,首先确定内层、外层平均粒径和内层模型尺寸,可提高参数匹配效率,最终选取内层、外层平均粒径为2 mm、3 mm,外内层体积比为7.00。岩石分层模型可以表现出与室内试验相同的单轴压缩力学特性以及宏观破裂特征,破坏方式均为张拉-剪切混合破坏,分层结构不会对裂纹由细观向宏观发展产生异常影响。In the particle distinct element method,using modeling method with different size scales inside and outside(layered model)can reduce computational complexity and effectively improve the accuracy of calculations,thereby modeling and calculating was conducted on problems in large-scale engineering such as tunnels and slopes.Although the layered modeling method is feasible in model generation and contact allocation,it is still unknown whether its mechanical properties under loading conditions is same as that of the conventional model and how about the matching degree is between calculation results and indoor tests.The effectiveness of the rock layered model for uniaxial compression test was analyzed from the macro and meso perspective,and the influences of the outer and inner layer average particle size ratios and the size of the inner layer model on the compressive strength of the layered model were explored.The research results show that the layered structure of the layered model won't have an abnormal effect on its macro mechanical properties under uniaxial compression.Force can be transmitted normally at the interface between layers,but the layered structure will make the model absorb,store,and consume more energy.The uniaxial compressive strength of the layered model increases with the increase of outer and inner layer average particle size ratio.As the volume of the inner layer increases,the uniaxial compressive strength of the layered model shows a trend of first increasing and then decreasing.When the layered model is used to match the uniaxial compressive strength of the rock specimen,the average particle sizes of the inner and outer layer and the volume of the inner layer model need to be determined first to improve the efficiency of parameter matching.The average particle sizes of the inner and outer layers were ultimately selected to be 2mm and 3mm,respectively,with an outer and inner volume ratio of 7.00.The rock layered model can show the same uniaxial compression mechanical properties and macroscopic

关 键 词：分层模型 离散元 单轴压缩试验 力学特性 破裂特征 

分 类 号：TD315[矿业工程—矿井建设]