考虑滚动阻抗的线性接触模型离散元宏细观参数敏感性研究  

Study on sensitivity of macro and micro parameters of discrete element in linear contact model considering rolling resistance

作　　者：马少坤[1,2] 黄骁 韦榕宽 刘莹[1,2] 段智博 MA Shaokun;HUANG Xiao;WEI Rongkuan;LIU Ying;DUAN Zhibo(College of Civil Engineering and Architecture,Guangxi University,Nanning Guangxi 530004,China;Key Laboratory of Disaster Prevention and Structural Safety,Guangxi University,Nanning Guangxi 530004,China)

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004 [2]广西大学工程防灾与结构安全重点实验室,广西南宁530004

出　　处：《中国安全生产科学技术》2021年第6期104-110,共7页Journal of Safety Science and Technology

基　　金：国家自然科学基金项目(41362016,51678166,51968005);广西岩土力学与工程重点实验室开放基金项目(16-KF-01);广西自然科学基金重点项目(2020GXNSFDA238024);广西研究生教育创新计划项目(YCBZ2020024)。

摘　　要：为克服无黏性土的离散元研究中未考虑颗粒间抗转动作用的缺陷,基于抗转动线性接触模型开展一系列排水固结三轴压缩模拟试验,结合随机森林算法详细探讨抗转动线性接触模型中各细观参数(有效模量、刚度比、摩擦系数、抗转动系数)与试样的宏观参数(初始弹性模量、泊松比、峰值强度)间的关系。结果表明:颗粒有效模量的提高会使试样的初始弹性模量提高而泊松比提高,权重值分别为0.69514和0.20157;刚度比的增加会使试样的初始弹性模量降低而泊松比提高,权重值分别为0.751和0.19364;抗转动系数与摩擦系数提高会显著提高试样的抗剪强度,权重值分别为0.56472和0.4275;抗转动系数对试样的剪胀性具有显著影响。In order to overcome the defect of ignoring the rolling resistance between particles in the discrete element research of cohesionless soil,a series of drained consolidation triaxial compression simulation tests were conducted based on the rolling resistance linear contact model,and the relationship between the micro parameters(effective modulus,stiffness ratio,friction coefficient and rolling resistance coefficient)and macro parameters(initial elastic modulus,Poisson’s ratio,peak strength)of the samples in the rolling resistance linear contact model was discussed in detail combining with the random forest algorithm.The results showed that with the increase of the effective modulus of particles,the initial elastic modulus of the sample increased,while the Poisson’s ratio decreased,and the weights was 0.69514 and 0.20157,respectively.With the increase of stiffness ratio,the initial elastic modulus of the sample decreased,while the Poisson’s ratio increased,and the weights was 0.751 and 0.19364,respectively.The increase of rolling resistance coefficient and friction coefficient would significantly increase the shear strength of the sample,and the weights was 0.56472 and 0.4275,respectively.The rolling resistance coefficient had significant influence on the dilatancy of the sample.

关 键 词：离散元 抗转动作用 宏细观参数 敏感性分析 

分 类 号：X947[环境科学与工程—安全科学] TU43[建筑科学—岩土工程]