锚固充填节理剪切试验与数值模拟研究

    EXPERIMENTAL AND NUMERICAL SIMULATION RESEARCH OF SHEAR CHARACTERISTICS OF INFILLED ROCK JOINTS REINFORCED BY ROCK BOLT

    • 摘要: 为探究充填物厚度和锚固结构联合作用对节理岩体剪切特性的影响,开展室内剪切试验和离散元数值模拟研究。首先制备类岩石材料节理试件进行室内剪切试验,结果表明,锚固结构在破坏前可显著提高节理岩体试件的峰值剪应力;随着充填物厚度增大,节理岩体试件的峰值剪应力减小,而锚杆的极限剪切位移会增大。建立不同充填物厚度的锚固充填节理数值模型,通过数值模拟进一步分析法向应力与锚固结构对剪切位移、峰值剪应力、法向位移、细观裂纹的影响。宏观结果表明法向应力越小,法向位移越大即剪胀越明显,且加锚试件的法向位移会高于无锚试样。细观结果则显示出试样的总裂纹数量随法向应力的增大而增大,且加锚试样的总裂纹数量明显高于无锚杆试样。

       

      Abstract: Laboratory shear tests and discrete element numerical simulation were carried out to investigate the effect of infilled thickness and bolting structure on the shear characteristics of jointed rock mass. The results of laboratory tests show that the peak shear stress of jointed rock mass specimens can be significantly increased by bolting structure before it failure. With the increase of infilled thickness, the peak shear stress of jointed rock specimen decreases, while the ultimate shear displacement of bolt increases. The numerical models with different infilled thicknesses were established, and the influence laws of shear displacement, peak shear stress, normal displacement and microscopic crack were analyzed by numerical simulation. The macroscopic results show that the smaller the normal stress is,the larger the normal displacement is. The normal displacement of the bolted infilled joint is larger than that unbolted. The microscopic results showed that the total number of cracks increases with the increase of normal stress, and the total number of cracks in the bolted specimens is significantly higher than that in the unbolted specimens.

       

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