| 考虑转动阻抗的粗粒土离散元模拟 |
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| 引用本文： | 刘一鸣,杨春和,霍永胜,刘 录,徐玉龙,杜 超.考虑转动阻抗的粗粒土离散元模拟[J].岩土力学,2013,34(Z1):486-493. |
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| 作者姓名： | 刘一鸣 杨春和 霍永胜 刘 录 徐玉龙 杜 超 |
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| 作者单位： | 1. 中国科学院武汉岩土力学研究所 岩土力学与工程国家重点试验室，武汉430071；2. 中国石油西气东输管道公司，江苏 常州 213251； 3. 中国石油天然气管道工程有限公司，河北 廊坊 065000; 4. 重庆大学 煤矿灾害动力学与控制国家重点实验室，重庆 400044 |
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| 摘 要： | 转动阻抗被定义为作用颗粒接触上的一对对称力偶，用来抵抗颗粒之间的相互转动。将转动阻抗引入到离散元模拟中是对传统离散单元法的重要改进。开发出考虑颗粒转动阻抗的接触模型，并将其嵌入到PFC2D中，利用该模型进行粗粒土的双轴剪切数值模型试验，研究剪切过程中转动阻抗对粗粒土的宏细观力学性质的影响。结果显示，在宏观方面，颗粒转动阻抗对粗粒土的宏观力学行为（应力-应变及体应变-轴应变行为）有重要的影响，随着转动阻抗的增加，粗粒土的剪切强度和最大摩擦角随之增加，这与已有的研究结果一致，证明所建模型是可靠的；在微观方面，考察转动阻抗对粗粒土内部微观结构的影响发现，随着转动阻抗的增加，粗粒土的内部的接触数目减少，而粗粒土的剪切强度增加，表明转动阻抗能够提高粗粒土力链网络的稳定性，同时发现随着转动阻抗的增加，粗粒土的各向异性增加主要是强力链各向异性的增加，说明转动阻抗增强了强力链的传递力的能力以及抵抗力链屈曲破坏能力。数值模拟结果表明，增加颗粒转动阻抗，粗粒土出现组构与轴应变非共轴的现象。
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| 关 键 词： | 离散元法 转动阻抗 双轴剪切试验 组构 |
| 收稿时间： | 2013-01-18 |
Discrete element modeling of behaviors of coarse grained soils considering rolling resistance |
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| LIU Yi-Ming,YANG Chun-He,HUO Yong-sheng,LIU Lu,XU Yu-long,DU Chao.Discrete element modeling of behaviors of coarse grained soils considering rolling resistance[J].Rock and Soil Mechanics,2013,34(Z1):486-493. |
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| Authors: | LIU Yi-Ming YANG Chun-He HUO Yong-sheng LIU Lu XU Yu-long DU Chao |
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| Institution: | 1.State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China; 2. Petro China West-to-East Gas Pipeline Company, Changzhou, Jiangsu 213251, China; 3. Petro China Pipeline Engineering Corporation, Langfang, Hebei 065000, China; 4. State Key Laboratory for Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; |
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| Abstract: | Rolling resistance is a force couple transferred between two contact particles, which is used for resistance particle mutual rotation. It is an important modification to introduce rolling resistance into discrete element method. In this paper a contact model considering rolling resistance is developed and installed into PFC2D. Using this model, a series numerical model of biaxial shear tests of course-grained soil are carried out to investigate the effects of rolling resistance on the macro- and meso- mechanical responses of particle assemble. The results show that: (1) In macro scope, the shear strength and volumetric response are increased with rolling resistance which is consistent with former researches, and this confirms the validation of the model used in this paper. (2) In meso-scope, the effects of rolling resistance on microstructure of coarse grained soils are investigated; the results show that contact numbers decrease with increasing of rolling resistance; while the shear strength are just to the contrary, that means rolling resistance enhances the stability of force chain network of coarse grained soils. The results show that the contribution of increasing anisotropy with increasing rolling resistance belongs to strong force chain. That confirms that rolling resistance improves the force transmitting ability and resistance of force chain buckling failure of strong force chain. And non-coaxial phenomenon is also observed in this study. |
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| Keywords: | discrete element method rolling resistance biaxial shear test fabric |
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