ISSN 1000-3665 CN 11-2202/P
    缪逢晨,王志亮,孙盼,等. 锦屏大理岩动态劈裂拉伸破坏及能量演化特征分析[J]. 水文地质工程地质,2024,51(0): 1-8. DOI: 10.16030/j.cnki.issn.1000-3665.202211033
    引用本文: 缪逢晨,王志亮,孙盼,等. 锦屏大理岩动态劈裂拉伸破坏及能量演化特征分析[J]. 水文地质工程地质,2024,51(0): 1-8. DOI: 10.16030/j.cnki.issn.1000-3665.202211033
    MIAO Fengchen, WANG Zhiliang, SUN Pan, et al. Analysis of dynamic splitting tensile failure and energy evolution characteristics of Jinping marble[J]. Hydrogeology & Engineering Geology, 2024, 51(0): 1-8. DOI: 10.16030/j.cnki.issn.1000-3665.202211033
    Citation: MIAO Fengchen, WANG Zhiliang, SUN Pan, et al. Analysis of dynamic splitting tensile failure and energy evolution characteristics of Jinping marble[J]. Hydrogeology & Engineering Geology, 2024, 51(0): 1-8. DOI: 10.16030/j.cnki.issn.1000-3665.202211033

    锦屏大理岩动态劈裂拉伸破坏及能量演化特征分析

    Analysis of dynamic splitting tensile failure and energy evolution characteristics of Jinping marble

    • 摘要: 岩石的劈裂破坏是深部隧洞岩体结构失稳破坏的主要形式之一。现阶段,岩石在动态劈裂条件下其裂纹扩展及对应阶段的能量演化机制鲜有涉及。基于此,对大理岩试样采用变截面分离式霍普金森压杆进行了不同弹速下的劈裂试验。借助ANSYS/LS-DYNA有限元软件模拟了试样动态劈裂破坏过程。结合试验数据和数值模拟结果,重点分析大理岩劈裂过程中的裂纹扩展机制以及能量演化特征。结果表明:在应变率为5 s−1~35 s−1时,大理岩的动态拉伸强度与应变率呈线性正相关,同其它地区大理岩相比较,锦屏大理岩的应变率敏感性相对较低;随着弹速的增加,系统内能和动能均增大,在试样破坏的瞬间系统内能降至最低;经过标定后的Cowper-Symonds本构模型应用于数值模拟,其模拟所得的最终破坏形态与试验观察到的现象基本一致。本文研究结果可为实际工程条件下的开挖与数值研究提供理论参考。

       

      Abstract: Splitting damage to rock is one of the main forms of structural destabilisation damage in deep tunnels. The mechanisms of crack extension and the energy evolution of the corresponding stages in rocks under dynamic splitting conditions have rarely been addressed. In this study, the splitting tests were carried out on the rock samples using a variable-section split-Hopkinson pressure bar at different striking velocities, and the dynamic splitting damage processes of the samples were simulated with ANSYS/LS-DYNA finite element software. Combining the experiment and numerical simulation, the crack extension mechanism and energy evolution characteristics during the splitting process of marble were analyzed. The results show that the dynamic tensile strength of the marble is linearly related to the strain rate in the range of 5 s−1 to 35 s−1, and the strain rate sensitivity of the marble is relatively low compared with the marbles of other regions. As the striking velocity increases, both the internal energy and kinetic energy of the system increase. At the moment of sample failure, the internal energy of the system drops to a minimum. The calibrated Cowper-Symonds intrinsic model was applied to the numerical simulations and the final damage patterns obtained from the simulations were in general agreement with the phenomena observed in the tests. This study can provide a theoretical information for excavation and numerical studies under practical engineering conditions

       

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