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工程科学与技术:2022,54(3):46-54
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基于直剪试验的堆积碎石类材料细观参数标定方法及模拟验证
(1.四川大学 水利水电学院,四川 成都 610065;2.四川大学 水力学与山区河流开发保护国家重点实验室,四川 成都 610065)
Mesoscopic Parameter Calibration Method of Accumulated Debris Materials Based on Direct Shear Test and Simulation Verification
(1.College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China;2.State Key Lab. of Hydraulics and Mountain River Eng., Chengdu 610065, China)
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投稿时间:2021-05-17    修订日期:2021-10-22
中文摘要: 颗粒材料的3维离散元数值模拟的可靠性取决于细观参数的合理标定。目前,对颗粒材料细观模拟参数的标定方法还缺少系统性的研究。本文通过对室内直剪试验和数值模拟的对比分析,揭示了碎石颗粒材料宏观力学参数与颗粒间细观参数的相关性,提出碎石颗粒材料数值模拟细观参数的标定方法,并验证该标定方法的合理性。结果表明:在线性模型中,碎石颗粒试样的宏观弹性常数与碎石的粒间法向接触刚度呈正相关,而对粒间切向接触刚度的变化不敏感;基于此提出的粒间接触刚度(法向、切向)标定方法,直剪数值模拟的剪应力–剪位移曲线计算结果与室内试验值吻合度较高,验证了该标定方法的可靠性及合理性。在直接剪切过程中,碎石颗粒内部力链网络随着剪位移的增加逐渐由垂直方向向剪切盒对角线方向偏转,随着颗粒的整体速度场变化而出现剪缩和剪胀现象;采用本文提出的细观参数标定方法对室内滑坡运动试验开展数值模拟,数值模拟的滑坡碎石堆积形态与室内试验结果基本一致,验证了该方法在堆积碎石滑坡模拟分析中的适用性。
Abstract:The reliability of three-dimensional discrete element numerical simulation of granular materials depends on the reasonable calibration of mesoscopic parameters. At present, systematic research on the calibration method of mesoscopic parameters is lacking. Based on the comparative analysis of indoor direct shear test and numerical simulation, the correlation between the macroscopic mechanical parameters of granular materials and the mesoscopic parameters of particles was revealed. Besides, the calibration method of the meso parameters of the numerical simulation of granular materials was proposed, and the rationality of the calibration method was verified. The research result showed that: in the linear model, the macro elastic constant of the sample was positively correlated with the normal contact stiffness of the particles, but not sensitive to the change of the tangential contact stiffness. Based on this, the calibration method of contact stiffness (normal and tangential) of particles was proposed. The shear stress-shear displacement curve of the numerical direct shear test was well agreed with the experimental value, so the reliability and rationality of the calibration method were verified; Through the numerical test of the direct shear of gravel, it was found that the internal force chain network of the particles deflected from the vertical direction to the diagonal direction of the shear box with the increase of shear displacement, and the shear shrinkage and expansion occurred with the change of the overall velocity field of the particles during the shear process. The meso parameter calibration method proposed was used to conduct a numerical simulation of an indoor landslide motion test. The morphology of landslide gravel accumulation in the numerical simulation was consistent with the indoor test result, which verified the applicability of the calibration method in the simulation analysis of accumulated gravel landslide.
文章编号:202100470     中图分类号:TU41    文献标志码:
基金项目:国家重点研发计划项目(2017YFC1501103);中国博士后科学基金面上资助项目(2019M653402)
作者简介:第一作者:杨文剑(1998—),男,硕士生. 研究方向:岩石力学参数及岩土工程数值模拟. E-mail:yangwenjian@stu.scu.edu.cn;通信作者:刘怀忠, E-mail:huaizhong.liu@scu.edu.cn
引用文本:
杨文剑,刘怀忠,谢红强,肖明砾,卓莉.基于直剪试验的堆积碎石类材料细观参数标定方法及模拟验证[J].工程科学与技术,2022,54(3):46-54.
YANG Wenjian,LIU Huaizhong,XIE Hongqiang,XIAO Mingli,ZHUO Li.Mesoscopic Parameter Calibration Method of Accumulated Debris Materials Based on Direct Shear Test and Simulation Verification[J].Advanced Engineering Sciences,2022,54(3):46-54.