ISSN 1003-8035 CN 11-2852/P

    加锚贯通节理岩体宏细观剪切破坏特性

    Macroscopic and microscopic shear failure characteristics of anchored penetrating jointed rock mass

    • 摘要: 为了研究加锚贯通节理岩体的剪切破坏特性,根据室内实验及数值模拟软件PFC2D,分析了不同法向应力及不同锚固角度作用下,加锚贯通节理岩体的抗剪性能及内部细观裂纹的演变过程。研究表明:(1)随着锚固倾角的增加,加锚节理岩体抗剪强度呈现先增大后减小的趋势,且在锚固角度为60°时,其抗剪强度最大,锚固效果最好。随着法向应力越大,加锚节理岩体抗剪强度越高,其抗剪性能越好。(2)随着剪切位移的不断增加,由初期阶段在锚杆和节理附近产生的少量裂纹通过不断的向外扩展,最终在锚杆和节理交界处聚集了大量的裂纹,其中裂纹以张拉裂纹为主。(3)锚固角度及法向应力对裂纹扩展影响显著,随着法向应力的增加,裂纹数也呈现了增加的趋势,且岩体破坏越严重。随着锚固角度的变化,加锚节理岩体破坏时形成的裂纹数量有先减小后增大的趋势,且在锚固角度为60°时,产生的裂纹最少。

       

      Abstract: In order to study the shear failure characteristics of anchored jointed rock mass, according to the indoor test and particle flow software PFC2D, the shear behavior and internal meso-crack evolution of the anchored rock mass under different normal stresses and different anchoring angles are analyzed. The researches show that: (1) With the increasing of the anchoring angle, the shear strength of the anchored rock mass increases first and then decreases, and when the anchoring angle is 60°, the shear strength is the largest and the anchoring effect is the best. With the higher the normal stress, the higher the shear strength of the anchored jointed rock mass, the better the shear resistance. (2) As the shear displacement increasing, a small number of cracks generated in the early stage near the anchor and joints, through continuous outward expansion, eventually gather a large number of cracks at the joint between the anchor and the joint, where in the crack, the tensile crack is dominant. (3) The anchoring angle and normal stress have a significant influence on crack propagation. With the increasing of normal stress, the number of cracks also shows an increasing trend, and the rock mass damage is more serious. With the change of the anchoring angle, the number of cracks formed when the anchored rock mass is destroyed firstly decreases and then increases, and when the anchoring angle is 60°, the cracks are the least.

       

    /

    返回文章
    返回