| 黏性材料细观与宏观力学参数相关性研究 |
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| 引用本文： | 周博,汪华斌,赵文锋,李纪伟,郑必灿.黏性材料细观与宏观力学参数相关性研究[J].岩土力学,2012,33(10):3171-3178. |
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| 作者姓名： | 周博 汪华斌 赵文锋 李纪伟 郑必灿 |
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| 作者单位： | 1. 华中科技大学 土木工程与力学学院，武汉 430074；2. 华中科技大学 岩土与地下工程研究所，武汉 430074 |
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| 基金项目： | 国家自然科学基金项目(No.420772170);广东省交通厅科技项目(No.2011-02-028);广东省交通厅政府引导项目(No.200903006) |
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| 摘 要： | 岩土工程数值模拟技术中参数选取的正确性是反应材料真实力学特性的基本前提。借助于颗粒离散元分析软件PFC2D，对黏性土类材料样本开展了大量的平面双轴压缩试验。通过记录不同围压下样本的轴向应力峰值，并依据摩尔-库仑强度准则对数值试样的剪切强度参数（内摩擦角、黏聚力）进行标定。着重探讨了黏性材料细观参数中颗粒刚度比kn /ks（0.5～10共12组）、颗粒粘结强度SBS（0～50 kPa共12组）、颗粒摩擦系数?（0～6共16组）以及颗粒粘结强度比K（0.1～10共15组）和材料宏观剪切强度参数以及材料剪切特性之间的相关性。研究结果表明：颗粒粘结（法向、切向）强度同对材料黏聚力呈线性相关；颗粒摩擦系数与材料内摩擦角呈近似对数相关；颗粒刚度比大小对材料剪切强度参数变化亦有微弱的影响；此外，K值（切向粘结强度/法向粘结强度）是影响材料的剪切破坏形态的重要因素。最后，采用了两个多元非线性拟合公式，定量地描述了以上各细观参数和材料宏观剪切强度参数的联合关系，并给出了K值的建议取值，为后续的研究提供重要的理论基础。
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| 关 键 词： | 离散元 颗粒流程序 细观参数 双轴压缩实验 |
| 收稿时间： | 2011-06-03 |
Analysis of relationship between particle mesoscopic and macroscopic mechanical parameters of cohesive materials |
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| ZHOU Bo
,
WANG Hua-bin
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ZHAO Wen-feng
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LI Ji-wei
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ZHENG Bi-can.Analysis of relationship between particle mesoscopic and macroscopic mechanical parameters of cohesive materials[J].Rock and Soil Mechanics,2012,33(10):3171-3178. |
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| Authors: | ZHOU Bo WANG Hua-bin ZHAO Wen-feng LI Ji-wei ZHENG Bi-can |
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| Institution: | 1. College of Civil Engineering and Mechanics, Huazhong University of Science and Technology, Wuhan 430074, China; 2. Institute of Geotechnical and Underground Engineering, Huazhong University of Science and Technology, Wuhan 430074, China |
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| Abstract: | In numerical simulation of geotechnical engineering,it is a priority to correctly select parameters,which reflects the real mechanical behavior of materials.Within the scope of particle flow code(PFC2D) as the particle discrete element method theory,a number of plane biaxial compression simulation tests are carried out for cohesive materials in the present study.According to peak axial stresses recorded under different confining pressures,internal friction angles and cohesions of specimens are defined following the Mohr-Coulomb strength criterion.After analysis of the simulation data,the relationship is interpreted between particle mesoscopic parameters of cohesive materials,including particle stiffness ratio of 0.5 to 10,particle bond strength of 0 to 50 kPa,particle friction coefficient from 0 to 6,particle bond strength ratio of 0.1 to 10,and material macroscopic shear strength parameters.The result shows that particle friction coefficient is logarithmically related to the internal friction angle of material;and particle bond strength is linearly related to the cohesion of materials.It is also noted that particles stiffness ratio and particle bond strength ratio have slight influences on material mechanical parameters;and the particle bond strength ratio significantly affects the shear failure form of the materials.Two final formulas are then established for the quantitative combined relationship between particle mesoscopic parameters and macroscopic shear strength parameters of cohesive materials after multiple nonlinear fitting.In these formulas,the proposal value of particle bond strength ratio is given for the mechanism of cohesive materials. |
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| Keywords: | discrete elements particle flow code mesoscopic parameters biaxial compression test |
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