摘要
颗粒破碎是土石混合体的一种基本属性,机理复杂,影响因素众多。鉴于室内试验受设备、材料等因素限制且费时费力,本文采用Monte Carlo思想构建了能够真实反映块石破碎过程的PFC 2D颗粒离散元数值模型,在室内直剪试验和筛分试验基础上进行了数值剪切试验,系统性探究土石混合体块石破碎特性的影响因素及基本规律。结果表明:在法向应力作用下,剪切后试样出现明显的块石破碎现象以分散应力;块石粒径对块石破碎程度影响显著,块石粒径越大,破碎势越大,越易破碎;块石浑圆度较小时,颗粒间接触面积较小,应力集中显著,破碎率较大;颗粒级配连续、良好时,颗粒间咬合充分接触完全,接触受力点较多,碎裂更不易发生;试样初始孔隙率对破碎率影响较小,相同法向应力下,随着孔隙率增大,块石破碎程度呈现轻微增大趋势。
As a basic attribute of Soil-Rock Mixtures(S-RMs),particle breakage has complex formation mechanism and many influencing factors.To systematically explore the influencing factors and basic laws of the breakage characteristics of S-RMs,we construct a PFC 2D particle discrete element numerical model by the thought of Monte Carlo.The model can truly reflect the breakage process of the rock block.Based on the indoor direct shear test and screening test,we carry out a series of numerical shear tests.The results show that:the sample appears obvious breakage phenomenon after shearing to disperse stress.The diameter of rock block has a significant effect on the breakage degree of rock block.The larger the diameter of rock block is,the greater the breakage potential is,and the easier it is to be broken.When the edges and corners of rock block are obvious,the stress concentration degree is stronger,and the breakage rate is larger.When the grain group is continuous and good,the particles contact more and completely,so the interface is larger and the breakage is less likely to occur.The initial porosity of the sample has little effect on the breakage rate.Under the same normal stress,with the increase of porosity,the breakage degree of the rock block shows a slight increasing trend.
作者
雷晓丹
杨忠平
翟航
胡元鑫
LEI Xiaodan;YANG Zhongping;ZHAI Hang;HU Yuanxin(Department of Architectural and Environmental Engineering,Taiyuan University,Taiyuan 030032,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Ministry of Education,Chongqing University,Chongqing 400045,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China;National Joint Engineering Research Center for Prevention and Control of Environmental Geological Hazards in the TGR Area,Chongqing University,Chongqing 400045,China;China Ordance Industry Survey&Geotechnical Institute Co.,Ltd.,Beijing 100053,China;Headquarters of Chongqing Yuwu Airport,Chongqing 401120,China)
出处
《工程地质学报》
CSCD
北大核心
2020年第6期1193-1204,共12页
Journal of Engineering Geology
基金
国家重点研发计划项目(资助号:2018YFC1504802)
国家自然科学基金项目(资助号:41772306)
中央高校基本科研业务费(资助号:2019CDXYTM0032).
作者简介
第一作者:雷晓丹(1993-),女,硕士,助教,主要从事岩土材料基本力学性质与边坡稳定性方面的研究.E-mail:Lei_xiaodan@163.com;通讯作者:杨忠平(1981-),男,博士,教授,博士生导师,主要从事环境岩土与边坡稳定性方面的教学与研究工作.E-mail:yang-zhp@163.com。
