| 摘要: |
| 借助颗粒流程序（PFC）建立了模拟含有交错节理岩石试样破坏的几何模型，对试样宏观力学参数进行标定，在编制了伺服模块的基础上，模拟了试样在不同法向应力条件下的直剪强度变化。采用软件内置的fish语言编制了裂纹扩展过程监测模块，从细观角度描述了交错节理试样在直剪过程中的裂纹扩展规律和破坏模式，并通过追踪微裂纹的数量对试样破坏规律进行量化分析。结果表明，试样剪切应力-剪切位移曲线主要分为4个阶段，随着法向应力和剪裂角的增大，剪切强度线性增加。试样裂纹主要产生在节理处，表现为中间夹块和上下节理凸起破坏，剪裂角对试样破坏规模有重要影响。相比单节理试样，交错节理试样抗剪强度明显降低，破坏规律有所不同。同时进一步考虑了节理间摩擦性质差异的影响，分析发现试样节理间摩擦性越强，试样剪切强度和破坏规模越大。模拟试验结果可为复杂节理岩体力学性质的研究提供参考依据。 |
| 关键词: 交错节理 剪切强度 裂纹扩展 直接剪切试验 颗粒流程序（PFC） |
| DOI： |
| 分类号:TU452 |
| 基金项目:国家自然科学基金资助项目(11572246， 51179153)； 陕西省教育厅科研计划资助项目(17JS091)； 西安市城建专项资金支持项目（SJW2017 14） |
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| Particle flow simulation of staggered joint rock by direct shear tests |
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HUAN Jiuyang, ZHANG Zhiqiang, LI Ning
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Institute of Geotechnical Engineering， Xi'an University of Technology， Xi'an
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| Abstract: |
| Based on the particle flow code (PFC), a geometric model for simulating the failure mechanism of the rock specimen with staggered joints was developed in the study, and the macro mechanical parameters of the specimens were calibrated. On the basis of the servo module, the variation in the direct shear strength of the specimens under the conditions of different normal stresses was simulated. The monitoring module for the crack propagation was prepared by fish language inserted in the PFC. The crack propagation law and the failure mode of the specimens with staggered joints were described during the direct shearing process from microscopic point of view, in addition, a quantitative analysis of the failure law of the specimens was carried out by tracking the numbers of the microcracks. The model testing results show that the shear stress shear displacement curves are mainly divided into four stages, and along with the increase of the normal stress and the shear angle, the shear strength increases linearly. The cracks of the specimens mainly occur at the joints, which appear as break of intermediate blocks and upper and lower joint protrusions. And the shear angle has an important influence on the failure scale of the specimens. Compared with the single joint specimens, the shear strength and the failure scale of the specimens having the staggered joints decrease greatly but the failure law is different. The difference of the joint friction property has been further considered. From the model tests it is found that the stronger the friction in the joints, the greater the shear strength and the failure scale of the specimens. The simulation testing results given by this paper can provide a reference for the study of mechanical properties of the rock mass having complex joints. |
| Key words: staggered joint shear strength crack propagation direct shear test particle flow code (PFC) |
